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HP Switch 3588A User's Manual

1. Trace Type switches between a log magnitude or linear magnitude display Trace Data determines the type of data shown on the active display this can be current measurement data or stored data Scale adjusts the position and size of the displayed data Math lets you define math functions and constants to be used when performing math operations with measurement data Format selects the number of traces displayed and adjusts their appearance Pressing Format also lets you view the analyzer s setup state a listing of the analyzer s current measurement parameters 2 25 Front Panel Overview System Keys System Keys LLLELLLLLL i Keys The System keys let you control how the analyzer communicates the external devices the HP IB controller and external measurement programs Here s a brief summary of the System keys and their significant functions Help provides information about specific analyzer controls and functions see The Help Key later in this chapter Save Recall lets you save and recall stored traces instrument states limits math operations and HP INSTRUMENT BASIC programs Disk Utilities provides useful utilities to let you format delete and examine files stored on the currently selected mass storage device including the analyzer s internal RAM disks and flexible disk drive or external disks Special Functions lets you perform a calibrati
2. SWEEP TIME SAMPLE TIME OVERSWEEP ON OFF Trigger hardkey FREE RUN TRIGGER EXTERNAL TRIGGER HP 18 TRIGGER ARM AUTO MAN ARM Avg Peak Hid hardkey OFF VIDEO AVERAGE PEAK HOLD NUMBER AVERAGES Source hardkey SOURCE ON OFF SOURCE AMPLITUDE AMPLITUDE STEP 50 OHMS OUTPUT Z 75 OHMS OUTPUT Z COUPLE TO INPUT Z CLEAR SRCE TRIP 10 2 Menu Map Display Group Display Group Active Trace hardkey Format hardkey SINGLE UPPER LOWER FRONT BACK SETUP STATE GRATICULE ON OFF BLANK ANNOTATN BLANK DISPLAY Trace Data hardkey INPUT SPECTRUM FUNCTION F1 F5 Fx CONSTANT K1 K5 Kx DATA REG D1 D8 Dx NORMLIZED SPECTRUM SAVE NORM REFERENCE TRACE TITLE Math hardkey DEFINE F1 SPECTRUM c ENTER DATA REG D1 D8 DATA REG Dx CONSTANT K1 K5 CONSTANT Kx FUNCTION F1 F5 FUNCTION Fx SORT NBW DEFINE Fx DEFINE Kx 10 3 Menu Map Display Group Trace Type hardkey LOG MAGNITUDE LINEAR MAGNITUDE Scale hardkey AUTO SCALE VERTICAL DIV REF TRACK ON OFF REFERENCE LEVEL 104 Menu Map Marker Group Marker Group Marker hardkey MKR gt PEAK MKR gt CTR FREQ MKR gt REF LEVEL ZERO OFFSET MARKER X ENTRY NXT RI
3. Free Run Range Impedance Type Type Off Low Dist OFF Mode Coupling Gn Video Bid 26 9068 Hz 42 6 dE 18 dBm Aute Correction Level futorange On frm Ruto Number 16 2 27 Front Panel Overview The Preset Key Keep in mind that pressing Preset is not the same thing as turning off the analyzer and turning it on again a power up cycle There are some settings that are unaffected by preset but are changed when a power up cycle occurs These include Definitions of constants and functions Contents of data registers HP Instrument BASIC programs currently loaded Memory size Scratch option Renumber start and increment Secure start and end line Additionally there are even some settings that survive both Preset and power up You must change these settings from the front panel or via HP IB These settings include m Storage configuration default disk selection System controller mode system controller or addressable only HP IB Disk Printer and Plotter addresses Disk volume and unit numbers Time and date MARKER group _ Marke ey Marker Ecin ha X Entry 75 05 MH Peak Trk Off Offset Off Freq Cntr Off Marker On Noise Lvl Off DISPLAY group Active Trace ey Active Trace A Display Format Single Graticule On Meas Dat Trace A Input Spectrum Vertical Div 10 dB Trace B Input Spectrum Ref Track On Trace Title A default Trace Title B def
4. FAIL BEEP ON OFF is ON during limit testing an enabled beeper emits an audible tone when a trace falls outside the specified limits 9 8 Key Reference BLANK ANNOTATN softkey BLANK ANNOTATN softkey Key Path Format Each trace box is surrounded by fields that define the trace within that box These fields are collectively referred to as trace annotation Press the BLANK ANNOTATN softkey to turn this annotation off Note You must preset the analyzer to turn on blanked annotation from the front panel You must send DISP ANN ON over the HP IB to turn on blanked annotation without presetting Fields surrounding the trace box contain the following information m Directly above marker readouts a Directly below x axis labeling To the left y axis labeling When trace annotation is turned off these fields are not displayed on the screen and they are not printed or plotted BLANK DISPLAY softkey Key Path Format With the exception of the softkey labels all information on the analyzer s screen can be blanked turned off You can accomplish this by pressing the BLANK DISPLAY softkey Note You must preset the analyzer to turn on a blanked screen from the front panel You must send DISP ON over the HP IB to turn on a blanked screen without presetting When the screen is blanked the message Display Blanking On replaces all other information Only this message is plotted or printed
5. However this has one disadvantage the analyzer uses the offset value if the offset marker is on l MORECHARS softkeys Each MORECHARS softkey gives you access to special characters for alpha entry When you press one of these softkeys the characters listed after MORECHARS are displayed in a menu You can then insert one of these characters to the left of the text cursor by pressing the corresponding softkey O O O E OOO DO epee Note A CANCEL RETURN softkey is displayed so you can return to the alpha entry menu without inserting a special character _ eee UU MOVE ALL VERTICAL softkey Key Path Marker Fetn gt LIMIT TEST gt DEFINE UPPER LIM or Marker Fetn gt LIMIT TEST gt DEFINE LOWER LIM Press MOVE ALL VERTICAL when you want to move an entire limit up or down The value of MOVE ALL VERTICAL specifies an amplitude offset for every segment in the limit The offset is referenced to the limit s original position You can change the current value by turning the knob pressing an arrow key or entering a new value with a number key 9 72 Key Reference MOVE MKR HORIZNTAL softkey MOVE MKR HORIZNTAL softkey Key Path Marker Fetn gt LIMIT TEST gt DEFINE UPPER LIM or Marker Fetn gt LIMIT TEST gt DEFINE LOWER LIM Press MOVE MKR HORIZNTAL when you want to move the limit marker horizontally Limits are defined
6. INTRLEAVE FACTOR to define the ordering of sectors on the 3 5 inch flexible disks you will format in the internal disk drive An entry box is displayed so you can enter a new value Save and recall operations are more efficient faster when you select the proper interleave factor The analyzer s internal disk drive is most efficient when using disks formatted with an interleave factor of 1 You can change INTRLEAVE FACTOR in the usual ways but with the following conditions Any value you enter with the number keys is changed to the closest integer in the range 1 255 m When you turn the knob slowly or press an arrow key one time the current interleave factor changes by 1 Kx softkeys Key Path Trace Data gt CONSTANT K1 K5 Press one of the Kx softkeys to display the magnitude of the corresponding user defined constant ne Note Constants are defined under the Math hardkey Y LAST ERROR softkey Key Path User Define gt DEBUG Press LAST ERROR to redisplay the last error message generated by your HP Instrument BASIC program See also DEBUG softkey 9 56 Key Reference Limit registers Limit registers The analyzer has four limit registers one upper and one lower limit register for each of the two traces Each register holds a complete limit also called a limit line You can load a register either by creating a limit or by recalling a limit from one of the disks To
7. Note Some functions can not be used in the definition of another function Restrictions uj are described under the FUNCTION Fx softkeys FUNCTION F1 F5 softkey Trace Data Key Path Trace Data Press FUNCTION F1 F5 for access to the Fx softkeys Each Fx key displays the result of a function you have defined Note A function must be defined before it can be displayed Functions are defined under me the Math hardkey FUNCTION Fx softkeys Key Path Math gt DEFINE Fx gt FUNCTION F1 F5 When you are defining a function press one of the FUNCTION Fx softkeys to specify the contents of the corresponding function register as an operand The abbreviation Fx is added to the end of the definition except in the following case When you redefine a function you can insert the old definition of that function into the new one by selecting the corresponding FUNCTION Fx softkey For example assume that the old definition of F2 is SPEC K1 D1 If you press the FUNCTION F2 softkey while redefining F2 SPEC XK1 D1 is inserted into the new definition 9 45 Key Reference Fx softkeys Fx softkeys Key Path Trace Data gt FUNCTION F1 F5 Press one of the Fx softkeys to display the result of the corresponding user defined function Note A function must be defined before it can be displayed Functions are defined under g the Math
8. Swept Spectrum Measurements Zero Span Range 18 gpm 19 Mar 1998 15 37 Res Bu 17 208 Hz VB OFF Freq 18 399 BAB Hz Ed A ERIC Mkr 3 22 msec 16 76 mUrms A A a e murms E DEF Lintag pios PEE A A A ERAS AO A y A em id BEEPER Saty fee nes i TIME HAMM pare MMDDYY SERIAL HUMBER A A A E PRE A cues Pads Stop 6 4 mSec RE Overview In Zero Span mode the analyzer s local oscillator remains at a single frequency in other words the analyzer acts as a fixed tuned receiver This is similar to manual sweep mode But unlike manual sweep mode in which you examine a signal at a only one display point zero span lets you examine a signal on all 401 display points and in the time domain as well Zero span lets you view the amplitude of a test signal or amplitude modulation of a fixed carrier To tune to a desired frequency simply press CENTER and enter an appropriate frequency with the knob or the numeric entry keypad Zero Span is the only measurement type where measurement data is shown in the time domain not the frequency domain When looking at a zero span trace the vertical axis still represents amplitude but the horizontal axis represents time This lets you view the amplitude of a test signal versus time Here are a few applications Observing the amplitude modulation of a carrier frequency Checking the long term amplitude stability of a test signal Adjusting a filter or other network to pass or stop a par
9. The old definition is in effect until you complete the new one by pressing the operator menu s ENTER softkey Until you press ENTER you can abandon the new definition and retain the old one by pressing any hardkey or a CANCEL RETURN softkey The Back Space hardkey is used to correct mistakes lt deletes the last operand or operator in the new definition DEFINE Kx softkey Key Path Math The analyzer has five constant registers K1 through K5 Each register holds a trace math constant that you define To change the magnitude of a particular constant or to display its current magnitude press the corresponding DEFINE Kx softkey Use the numeric entry keys to change the value of the specified constant You can accept the new value by pressing the ENTER softkey Until you press ENTER you can reject the new value and retain the old one by pressing any hardkey or the CANCEL RETURN softkey DEFINE LOWER LIM softkey Key Path Marker Fetn gt LIMIT TEST DEFINE LOWER LIM displays a menu The softkeys in the menu allow you to define or alter the lower limit for the active trace You define the lower limit as a series of line segments Here s how you use the softkeys in this menu to define the segments m MOVE MKR HORIZNTAL This lets you define the frequency value of a segment endpoint MOVE MKR VERTICAL This lets you define the amplitude value of a segment endpoint m
10. You can define most plot parameters under the DEFINE PLOT softkey but you must change plot scaling parameters on the plotter itself Note Plots are only executed if the SYSTEM CONTROLLR softkey is selected and if the value entered under the PLOTTER ADDRESS softkey matches your plotter s HP IB address setting PLOT MARKER softkey Key Path Plot Print Press PLOT MARKER to plot every main marker that is currently displayed on the analyzer s screen Markers are annotated with their x axis and y axis coordinates You can define most plot parameters under the DEFINE PLOT softkey but you must change plot scaling parameters on the plotter itself Note Plots are only executed if the SYSTEM CONTROLLR softkey is selected and if the j value entered under the PLOTTER ADDRESS softkey matches your plotter s HP IB address setting 9 91 Key Reference PLOT OFFST MKR softkey PLOT OFFST MKR softkey Key Path piot Print Press PLOT OFFST MKR to plot every offset marker that is currently displayed on the analyzer s screen Markers are annotated with their x axis and y axis coordinates You can define most plot parameters under the DEFINE PLOT softkey but you must change plot scaling parameters on the plotter itself Note Plots are only executed if the SYSTEM CONTROLLR softkey is selected and if the g value entered under the PLOTTER ADDRESS softkey matches your plotter s
11. hardkey Goto Line softkeys Key Path User Define gt edit The GOTO LINE softkeys let you move the text cursor directly to a particular line of the program you are editing You can specify the line either by its number or its label Use the number keys to specify a line number Use the hardkeys with engraved letters the underscore _ softkey and the UPPERCASE lowercase softkey to specify a label Then when you press ENTER the text cursor moves to the specified line If you enter a line number that doesn t exist the cursor moves to the closest line If you enter a label that doesn t exist the cursor remains on the current line Hint To go to the end of the program enter a line number greater than that of the last line for example 99 999 GRATICULE ON OFF softkey Key Path Format Trace boxes can be overlaid with graticules or grids These graticules help you estimate the x and y values of a particular point on a trace You can toggle graticules on and off with the GRATICULE ON OFF softkey When graticules are turned off they are not displayed on the screen and they are not printed or plotted However borders remain to define the limits of the trace boxes 9 46 Key Reference GRATICULE PEN softkey GRATICULE PEN softkey Key Path Plot Print gt DEFINE PLOT gt DEFINE PLOT PENS Press GRATICULE PEN to specify which plotter pen should be used for plott
12. marker functions 6 1 9 65 9 66 See also main marker See also offset marker marker keys 2 20 marker readout 6 2 measurement keys 2 24 measurement restart 9 69 menumap 10 1 N narrow band zoom measurements 5 1 9 74 high accuracy zoom 5 2 high resolution zoom 5 2 See also swept spectrum measurements network measurements See scalar network measurements noise density See noise level noise level 6 7 9 75 and recalled traces 6 9 See also random noise spectral density special considerations 6 7 noise marker See noise level normalization See scalar network measurements numericentry 9 79 changing numeric parameters 9 14 entry box 2 20 with the knob 2 20 numeric entry keys 2 21 active entry 2 21 O offset marker 6 2 9 81 See also main marker offset to span 6 4 9 81 OVEN REF OUT See oven reference output oven reference output 3 5 oversweep 4 3 9 84 OVLD See input p peak detector 9 86 and the noise floor 4 13 disabling 4 13 peak detector the 4 11 peak hold 7 6 9 87 difference between peak track and signal track 7 6 Index Continued peak track 9 87 performance test 9 89 plotter page eject 9 85 plotting assigning pens 9 23 default pens 9 21 plot parameters 9 24 plotting printing measurement results 9 94 preset key 2 27 9 96 preset state 9 96 R radio receivers See spectrum analyzers and radio receivers random noise spectral density 6 8 RBW See resolution bandwidth REF OUT Se
13. normalization earlier in this chapter A math function can contain the current input spectrum a stored trace or a constant You can also use the square root of the current noise bandwidth NBW to generate a noise spectral density trace this is useful when you need an entire trace normalized to a 1 Hz bandwidth By the way NBW is a calculated value that changes with the current measurement setup you can see this value by viewing the setup state Special Considerations It s not difficult to use trace math but there are some things you should know before building your own math functions m Math functions are specified by entering the definition with operands and operators in infix standard algebraic notation u Constants must be defined as real numbers a To view the results of a trace math operation press Trace Data and use the appropriate softkeys to call up the results for a particular math function z To exit any math menu without affecting any function of constant definitions simply press any hardkey Measurement Enhancements Trace Math 7 4 Measurement Enhancements Video Averaging Video Averaging Overview When averaging is on the analyzer combines the results of the most recent measurement that is a single frequency sweep or one Narrow Band Zoom measurement to the accumulated results of previous measurements Once averaging is on it continues until you turn off averaging It does not s
14. ENTER DELETE LINE softkey Key Path User Define gt EDIT Press DELETE LINE to delete the line containing the text cursor when you are editing a program The deleted line is placed in a one line buffer You can recall the deleted line into another part of your program with the RECALL LINE softkey DELETE SEGMENT softkey Key Path Marker Fetn gt LIMIT TEST gt DEFINE UPPER LIM or Marker Fetn gt LIMIT TEST gt DEFINE LOWER LIM Press DELETE SEGMENT to delete one segment of a limit The analyzer deletes the segment that is vertically aligned with the limit marker If you pressed DEFINE UPPER LIM to enter the menu this key deletes a segment from the active trace s upper limit If you pressed DEFINE LOWER LIM to enter the menu this key deletes a segment from the active trace s lower limit 9 26 Key Reference Disk specifiers Disk specifiers The analyzer contains three different storage devices all referred to as disks So when you press a softkey that accesses a disk function you are prompted to specify which disk the function should act on Use the following disk specifiers a INT specifies the internal disk a RAM specifies the volatile RAM disk e NVRAM specifies the non volatile RAM disk When you press a softkey that prompts you for a filename you can prefix the filename with a disk specifier This allows you to access
15. If you load disks that are already formatted keep in mind that the disk drive recognizes only those disks that have been formatted using the Logical Interchange Format A Note The disk drive is designed for operation in a typical office environment Use of the equipment in an environment containing dirt dust or corrosive substances will drastically reduce the life of the disc drive and the flexible disks The disks should be stored in a dry static free environment Front Panel Overview Power Switch Power Switch The analyzer s power switch has two positions on and standby 4 In the standby position the analyzer appears off but line power is still applied to the instrument s power supply te H i awed sawed smal ped AO ane a md sed a Sac EEEN Spe Ye AA Jd mile aid saa O mr comme sd cod seed conan Power Switch 2 10 Front Panel Overview Hardkeys and Softkeys Hardkeys and Softkeys Softkeys Hardkeys Hardkeys are front panel buttons whose functions are always the same Hardkeys have a label printed directly on the key itself Throughout this book they are printed like this Hardkey Softkeys are keys whose functions change with the analyzer s current menu selection A softkey s function is indicated by a video label to the left of the key on the edge of the analyzer s screen The companion video labels to the left of the ten softkeys f
16. Key Reference SOURCE ON OFF softkey SOURCE ON OFF softkey Key Path Source Press this softkey to toggle the analyzer s source on and off When the source is off the output amplitude is approximately 100 dBm Note Oversweeping is automatically disabled when you turn the source is on The amplitude corrections that make oversweeping possible are not valid when a signal is sweeping with the receiver Yf you are using the source to make a scalar network measurement turn the peak detector off The peak detector is necessary for most spectrum measurements but introduces a slight frequency skew in scalar network measurements SOURCE DISK softkey See Copy Disk softkeys SOURCE FILENAME softkey See Copy File softkeys 9 126 Key Reference SPAN softkey SPAN softkey Key Path Freq Use SPAN to define the width of a frequency band you want to analyze CENTER and SPAN act together to define a frequency band the current value of one softkey is held constant when you change the value of the other You can also use START and STOP to define a band but CENTER and SPAN are more convenient when you are zooming in on a single peak in the spectrum Hint Press CENTER to change x axis labels from start stop to center span Certain combinations of CENTER and SPAN may define x axis limits that are outside the range of 0 to 150 MHz For example a lower limit of 5 MHz result
17. Note Signal tracking is not available for manual sweeps SINGLE softkey See Display Format softkey group trace 9 121 Key Reference SINGLE AUTORANGE softkey SINGLE AUTORANGE softkey Key Path Range input Press SINGLE AUTORANGE to autorange the analyzer when continuous autoranging is disabled Single autoranging selects the best range for the current input signal It changes the range once under these circumstances a Ifthe signal level is large enough to overdrive the input circuitry the analyzer selects a less sensitive input range Ifthe signal level is small enough to compromise dynamic range the analyzer selects a more sensitive range Note Autoranging is not possible when the 1 megohm input impedance is selected 4 SINGLE STEP softkey See DEBUG softkey SINGLE CAL softkey Key Path Spel Fetn Press SINGLE CAL to calibrate the analyzer one time Calibration starts as soon as you press the key interrupting any measurement in progress Note Enable the analyzer s autocalibration function if you want calibrations to occur s automatically 9 122 Key Reference SINGLE STEP softkey SINGLE STEP softkey Key Path User Define gt DEBUG Press SINGLE STEP to execute one line of your HP Instrument BASIC program The first time you press SINGLE STEP the analyzer performs a pre run operation and then displays the first line to be executed On su
18. Softkeys grouped under the Scale hardkey are used to alter the vertical scaling and vertical position of the active trace Horizontal scaling and position are determined by your measurement s center frequency and frequency span Change these values with softkeys grouped under Freq You can display trace data using either linear or logarithmic vertical coordinates You select one of these options with the softkeys grouped under Trace Type Scratch Options softkey group Key Path User Define gt utilities gt SCRATCH Press one of the softkeys in this group to specify what will be deleted when you press PERFORM SCRATCH Each softkey specifies some combination of your HP Instrument BASIC program and its variables m SCRATCH specifies the program and all of its variables except those in COM SCRATCHC specifies all program variables including those in COM but not the program itself m SCRATCH A specifies the program and all of its variables including those in COM SCRATCH softkey Key Path User Define gt UTILITIES SCRATCH displays a menu You use the softkeys in the menu to do two things m Select which combination of your HP Instrument BASIC program and its variables you want to delete m Delete the selected combination SCRATCH C softkey See Scratch Options softkey group SCRATCH A softkey See Scratch Options softkey group 9 119 Key Referenc
19. Status messages appear at the lower left corner of the screen These messages keep you informed about current measurement conditions Examples of status messages include m Averaging Waiting for trigger Waiting for arm m settling Taking data for spans less than 625 Hz narrow band zoom only Trace Title You can specify a trace title by pressing Trace Data TRACE TITLE and using the alpha shift keys and numeric keypad Range 8 dBm Res Bu 17 888 H BEE Trace M 29 Dec 1989 13 34 VER Off Swp time 524 8 mSec 73 526 B8 Bz 1 40 Em Front Panel Overview CRT care and cleaning CRT care and cleaning The analyzer s CRT is protected by a plastic screen that also provides RFI shielding During normal operating conditions the only cleaning that should be required is an occasional dusting with a soft brush A household type tack cloth or other type of lint remover may also be used If foreign material adheres to the screen dampen a soft lint free cloth moistened with a mild detergent diluted with water and carefully wipe the screen The plastic screen is not operator replaceable In the unlikely event that it becomes damaged contact your nearest Hewlett Packard Sales Service office Warning Do not apply any water mixture directly to the screen or allow moisture to z go behind the front panel Moisture behind the front panel will severely damage the instrument and may present a shock ha
20. The analyzer s resolution bandwidth must be narrow enough to resolve a relatively flat portion of the noise floor this is particularly important when you are measuring low frequency noise or phase noise a Ifyou re using a logarithmic magnitude trace type the analyzer expresses noise level in units of dBm Hz this is the amount of power for a 1 Hz wide spectrum For a linear magnitude trace type the analyzer expresses noise in units of V rt Hz that is volts per square root of Hertz 6 7 Marker Functions Noise Level 6 8 Marker Functions Noise Level Noise Measurements and Trace Data The noise level marker can only measure noise in the current input spectrum If you select trace data that is not linked to the current input spectrum for example the contents of a data register no noise value is displayed If you view trace data that is linked to the input spectrum for example a normalized spectrum or a function definition that uses an input spectrum the noise level marker is still available However the noise level reading will not be corrected to reflect the normalized measurement or math function performed Since the analyzer s noise level function provides noise density only at the current marker position you must use trace math to generate an entire trace normalized to a 1 Hz bandwidth To do this you can divide the input spectrum by the square root of the noise bandwidth NBW to generate a noise spect
21. To learn more about setting the step size to your best advantage see chapter 7 Measurement Enhancements When numeric entry is active an entry box appears at the top of the screen with the currently selected numeric value This box remains on screen for several seconds to give you a chance to enter a numeric value If you don t make an entry the box disappears after several seconds If you use the knob or alternatively the numeric entry keypad to make an entry this box remains on the screen After you complete your entry the box soon disappears and the knob returns to marker movement 2 20 Front Panel Overview Numeric Entry Keys Numeric Entry Keys emean somone eee m simo Numeric Entry Keys The numeric entry keys work the same way as the knob does during numeric entry Use the numeric entry keys when you need to enter specific values If you only need approximate values it may be easier to use the knob instead of the numeric entry keys Active Entry It isn t always necessary to first press a softkey before making a numeric entry A highlighted softkey is the softkey that is currently dedicated to the numeric keypad For example press Freq If the CENTER softkey is highlighted pressing any of the numeric keypad keys automatically brings up a numeric entry window for center frequency You don t have to press CENTER to set the center frequency 2 21 Front Panel Ov
22. UTILITIES gt RENUMBER Press PERFORM RENUMBER to renumber the lines of your HP Instrument BASIC program The number of the first line will be the value specified in START LINE 4 The increment between lines will be the value specified in INCREMENT 9 88 Key Reference PERFORM SCRATCH softkey PERFORM SCRATCH softkey Key Path User Define gt UTILITIES gt SCRATCH Press PERFORM SCRATCH to scratch delete your program and or its variables The selection you made in the Scratch Options softkey group determines what will be deleted See Scratch Options softkey group PERFORM SECURE softkey Key Path User Define gt UTILITIES gt SECURE Press PERFORM SECURE to secure the portion of your program specified by START LINE and END LINE Secured lines cannot be viewed in the HP Instrument BASIC editor or printed with PRINT PROGRAM An asterisk replaces program statements on secured program lines Caution Secured program lines can not be unsecured Be sure to keep an unsecured version Y of the program for your own records Performance test softkeys Key Path Spei Fetn The PRFM TESTS softkey displays a menu Use the softkeys in the menu to enable special hardware setups when you are testing the analyzer s performance Here are the softkeys in the Prim Tests menu u CALIBRATR TO INPUT J a SRCE 10d8 IN OUT J m SRCE 20dB A IN OU
23. accuracy use the frequency counter To learn more about the frequency counter see chapter 6 Measurement Enhancements To learn more about display resolution and frequency resolution see the sidebar on peak detection in chapter 4 Swept Spectrum Measurements 2 13 Front Panel Overview Display Area Status Indicator Area Range 2 dBm 29 Dec 1989 13 34 Res BR 17 949 2 VB Off Sup Time 524 8 mSec A Ee nkr 73 526 B89 Kz 1 43 dBm O RON NAAA RARA IRAN AP dan ran nba na Peete ninbrranqranmnrados Status Indicator Area From time to time various status indicators appear at the bottom right hand corner of the analyzer s screen The indicators are visible only while the conditions they represent remain active These status indicators are w RMT remote indicates the presence of an external device that has control of the analyzer s HP IB a SRQ service request indicates an analyzer request via HP IB to communicate with the current HP IB controller a UNCAL uncalibrated sweep indicates a condition where the current sweep time is too fast for the current resolution bandwidth RBW to ensure an accurate measurement m REF reference indicates the presence of an external frequency reference from either the analyzer s optional temperature controlled reference or an external reference signal RNG range indicates and under over range condition OVLD overload indicates an overload in the an
24. bandwidth coupling It is an important feature and one common to most swept tuned spectrum analyzers For example if you select a 100 kHz to 150 MHz span a large span the analyzer automatically selects a resolution bandwidth of 17 kHz If you select a 100 kHz to 200 kHz span a much smaller span the analyzer automatically selects a resolution bandwidth of 580 Hz Video bandwidth works the same way If you ve turned on video filtering the analyzer automatically selects an appropriate level of video filtering For example if you select a 100 kHz to 150 MHz span the analyzer selects a video bandwidth of 26 kHz When you select a 100 kHz to 200 kHz span the analyzer selects a video bandwidth of 900 Hz For most measurement situations bandwidth coupling provides the best compromise between frequency resolution and speed And for most measurements bandwidth coupling is generally preferable since it greatly simplifies your measurement setup Of course you can override these automatically selected settings at any time Changing Bandwidth Coupling You can easily override the current resolution bandwidth or video bandwidth selection by manually entering a setting of your own For example to use a different resolution bandwidth press Res BW RES BW and then use the numeric entry keys or the knob to specify a new resolution bandwidth setting anywhere from a maximum of 17 kHz to a minimum of about 1 Hz If you override a current
25. last changed time and date You can simplify many file operations by turning the catalog on When the catalog is on you can select one of the listed files with the knob Then when you request a file operation that prompts for a filename the name of the selected file is automatically placed in the prompt The catalog is turned off automatically when you do any of the following Eject a flexible disk whose catalog is being displayed m Press any hardkey in the MARKER DISPLAY or MEASUREMENT group m Press any hardkey other than Save Recail or Disk Util in the SYSTEM group 9 12 Key Reference CENTER softkey CENTER softkey Key Path Freg The function of the CENTER softkey depends on the analyzer s zero span state s Zero span selected The analyzer acts as a fixed tuned receiver CENTER tunes the receiver to the frequency you want to analyze a Zero span not selected The analyzer acts as a spectrum analyzer CENTER defines the center of a frequency band you want to analyze CENTER and SPAN act together to define a frequency band the current value of one softkey is held constant when you change the value of the other You can also use START and STOP to define a band but CENTER and SPAN are more convenient when you are zooming on a single peak in the spectrum Hint Press CENTER to change x axis annotation from start stop to center span The range of values for CENTER is
26. t you ve made are lost If the editor is in insert line mode when you press ENTER it creates a blank line below the current line and moves the text cursor to that new line If the editor is not in insert line mode when you press ENTER it just moves the text cursor to the next line of the program ENTER softkey The ENTER softkey is displayed when you are creating or editing a text string during alpha entry When you are done typing press ENTER to accept the new string Note You can abandon the new string by pressing CANCEL RETURN y ENTER is sometimes displayed when you are changing a numeric parameter with the number keys As with alpha entry you use it to accept the new value 9 34 Key Reference EXAMINE VARIABLE softkey EXAMINE VARIABLE softkey Key Path User Define gt DEBUG Press EXAMINE VARIABLE to view the contents of a program variable See also DEBUG softkey Note Your HP Instrument BASIC program must be paused stopped or in single step y mode before you can examine a variable When you press EXAMINE VARIABLE the analyzer prompts you to enter a variable name You enter a name using the alpha entry keys You can examine array variables in one of two ways Display the entire array by entering array_name in the entry box Display a single element of the array by entering lt array name gt lt element number gt The analyzer uses up to 10
27. 0 Hz to 150 MHz although the analyzer s performance in not specified below 10 Hz You can change CENTER s value in the usual ways but with the following enhancements u You can control the sensitivity of the knob and arrow keys with STEP SIZE AUTO USER and USER STEP SIZE You can set CENTER to the marker s current x axis value with the Marker Value hardkey Pressing the MKR gt CTR FREQ softkey has a similar effect Certain combinations of CENTER and SPAN can define x axis limits that are outside the range of 0 to 150 MHz For example a lower limit of 5 MHz results when CENTER 5 MHz SPAN 20 MHz When this happens any portion of a trace that falls outside the range is blanked not displayed z Change sign hardkey This hardkey has two functions When you are changing a numeric parameter Press this hardkey to toggle your entry between positive and negative values or to change the sign of an exponent a When you are changing a text string Press this hardkey to insert a dash or minus sign to the left of the cursor 9 13 Key Reference Changing numeric parameters Changing numeric parameters You can change the value of numeric parameters in the following ways e Enter a value with the number keys n Step the current value up or down with the arrow keys m Scroll the current value up or down with the knob Note Scrolling a value is similar stepping a va
28. 40 trigger output 3 8 Y VBW See video bandwidth video averaging 7 5 9 144 special considerations 7 5 See also video filtering video bandwidth 4 4 4 6 9 145 video filtering 4 4 4 6 See also video averaging W waveform math See trace math Z Zero response See local oscillator feedthrough zerospan 4 15 special considerations 4 16 zoom definition 9 147
29. HP IB address setting PLOT SPEED softkey Key Path Plot Print gt DEFINE PLOT Press PLOT SPEED for access to the plot speed softkeys The speed you specify with these softkeys will be used for all plot operations Note Check your plotter s documentation to be sure that it supports the requested rh plotting speed 9 92 Key Reference Plot Speed softkeys Plot Speed softkeys Key Path Plot Print gt DEFINE PLOT gt PLOT SPEED The plot speed softkeys let you specify the plotting speed for all plotting operations initiated by the analyzer Two softkeys provide the most commonly selected plotting speeds SLOW 10 cms FAST 50 cm s Two more softkeys let you request additional plotting speeds that may be supported by your plotter Press USER PLOT SPEED to enter a new speed units are cm s Press USER DEFINED to activate the user plot speed PLOT TRACE softkey Key Path PloVPrint Press PLOT TRACE to plot every trace that is currently displayed on the analyzer s screen Traces are plotted without graticules annotation or markers You can define most plot parameters under the DEFINE PLOT softkey but you must change plot scaling parameters on the plotter itself Note Plots are only executed if the SYSTEM CONTROLLR softkey is selected and if the value entered under the PLOTTER ADDRESS softkey matches your plotter s HP IB address se
30. ON The trace falls outside its current limits FINISH SEGMENT softkey Key Path Marker Fetn gt LIMIT TEST gt DEFINE UPPER LIM or Marker Fetn gt LIMIT TEST gt DEFINE LOWER LIM Limits are defined as a series of line segments Press FINISH SEGMENT to anchor a segment s ending point at the position of the limit marker Press START SEGMENT to anchor a segment s starting point Use MOVE MKR HORIZNTAL and MOVE MKR VERTICAL to position the limit marker When you press FINISH SEGMENT to anchor an ending point the analyzer automatically anchors the starting point of a new segment at the same position This makes it easier for you to build continuous limit lines Hint You can abandon the automatically generated starting point Just press START SEGMENT after you have repositioned the limit marker 9 37 Key Reference Fonts Fonts Fonts provide different ways to display the same character Here s how the fonts are used in the analyzer u Plain font This is used for most help text most softkey labels and for annotation of the active trace a Ghosted font This is used for annotation of the inactive trace and for labeling of inactive softkeys u Highlighted font inverse video This is used to indicate the active option for softkeys that toggle the active numeric entry softkey in a menu and the active link in help text Underlined font This is used to indi
31. Reference PEAK DET ON OFF softkey PEAK DET ON OFF softkey Key Path Meas Type Press PEAK DET ON OFF to enable and disable the analyzer s peak detector Note The peak detector should be on for all swept spectrum measurements It should be y off for scalar network measurements made with the tracking source The peak detector compensates for the limited frequency resolution of the analyzer s display Each trace box is divided along its x axis into 401 evenly spaced points which limits display resolution to 1 400th of the current span i The analyzer could not accurately display the amplitude of signals between display points if each point represented only a single frequency Signals could even be completely missed if the setting of resolution bandwidth was much narrower than the point spacing When the peak detector is on a display point represents all frequencies between its nominal frequency and the nominal frequency of the point to its right The amplitude of the largest signal detected in that band of frequencies is used as the amplitude of the point When the peak detector is off a display point represents a single frequency the nominal frequency of the point to its right All frequencies are shifted left by one display point Hint Use the frequency counter to measure the true frequency of a displayed peak Since the analyzer keeps positive peaks and rejects negative peaks when the peak detector is on the average
32. TYPING UTILITIES softkey TYPING UTILITIES softkey Key Path User Define gt EDIT The TYPING UTILITIES softkey displays a menu The menu and its submenus let you do the following things when you are editing a program Insert special characters w Insert keywords a Shift the case of alpha characters The Typing Utilities menu also repeats the ENTER INSERT SPACE and DELETE CHARACTER softkeys which are all available in the main editing menu Note The CANCEL RETURN softkey in the Typing Utilities menu just returns you to the t main editing menu It has no effect on the current line of your program O Underscore softkey See Goto Line softkeys UPPER LOWER softkey See Display Format softkey group trace UPPERCASE LOWERCASE softkey Press this softkey to toggle between upper case and lower case any time during alpha entry or program editing This softkey has the same function as a Caps or Caps Lock key on a standard keyboard it determines the case of alpha characters typed into a text string When UPPERCASE is highlighted all alpha characters you enter will be upper case A Z When lowercase is highlighted alpha characters will be lower case a z 9 140 Key Reference User Define hardkey User Define hardkey The User Define hardkey gives you access to all HP Instrument BASIC softkeys except those used to save and recall a program Note If th
33. a running HP Instrument BASIC program The softkeys grouped under this hardkey allow you to do the following things Abort HP IB operations initiated by the analyzer mM s Specify the analyzer s controller capabilities a Set the analyzer s address m Tell the analyzer what addresses you are using for attached peripherals m Specify whether HP IB mnemonics should be echoed to the display when equivalent keys are pressed a Interrupt a controller that is operating the analyzer via the HP IB When the analyzer is being operated via the HP IB all hardkeys on the analyzer s front panel except for Local HP IB are disabled You can press Local HP IB to suspend remote HP IB operation and reenable local front panel operation Note If the analyzer has received the Local Lockout command via the HP IB all me hardkeys are disabled In this case you can not reenable front panel operation by pressing Local HP IB The analyzer cancels any pending OPC command or query when you suspend remote operation See the HP 35884 HP IB Programming Reference for more information about remote operation of the analyzer 9 61 Key Reference LOG MAGNITUDE softkey LOG MAGNITUDE softkey Key Path Trace Type Press the LOG MAGNITUDE softkey when you want to display logarithmic magnitude on the y axis versus frequency or time on the x axis X axis units for this coordinate system are seconds when zero s
34. all HP IB interfaces it has used are reset and all open files are closed You can not continue a program that has been reset If you use SINGLE STEP after RESET execution begins at the first line of the program See also DEBUG softkey Note RESET does not affect your program s variables or HP Instrument BASIC s y display area 9 110 Key Reference RUN softkey RUN softkey Key Path User Define or User Define gt DEBUG Press RUN to begin execution of your HP Instrument BASIC program After all variables not in COM are initialized execution begins with the first statement Note If the program is paused you can resume execution by pressing CONTINUE E SAMPLE TIME softkey Key Path Sweep Press SAMPLE TIME to specify how long the analyzer should measure at a single frequency during manual sweeps An entry box is displayed so you can enter a new time Note The time between measurements can be significantly longer than the sample time You can change SAMPLE TIME in the usual ways but with the following conditions m The analyzer changes any value you enter with the number keys to the closest available value a The current sample time is changed by a factor of 2 when you turn the knob slowly or press an arrow key one time Hint Shorter sample times make it easier to use the knob for manual sweeping but longer times greater than 1 RBW ensur
35. analyzer However slightly inaccurate results may be occur when measuring non stationary signals The oversweep feature is not available when the analyzer s source is on If oversweep is on it will be turned off automatically when you turn on the analyzer s source this prevents slight measurement inaccuracies When you turn off the source oversweep resumes To turn off oversweep press Sweep and toggle to OVERSWEEP ON OFF To turn oversweep on again toggle to OVERSWEEP ON OFF J Resolution Bandwidth Resolution bandwidth often called RBW determines the analyzer s frequency resolution It also _ affects how fast the analyzer makes a measurement since resolution bandwidth affects the analyzer s sweep time Normally resolution bandwidth is adjusted automatically as you select different frequency spans Because resolution bandwidth also affects sweep time manually selecting a narrower resolution bandwidth can slow down a measurement more than necessary Selecting a resolution bandwidth that is too wide on the other hand does not provide adequate resolution and will obscure spectral components that are close together Resolution bandwidth is one of the most important parameter settings in a swept tuned spectrum analyzer To learn more about resolution bandwidth and what it does see the sidebar called Understanding Resolution Bandwidth and Video Bandwidth Swept Spectrum Measurements Video Filtering and Vi
36. as a series of line segments The limit marker s horizontal position defines the x axis value of a segment endpoint It s easiest to position the limit marker by turning the knob When MOVE MKR HORIZNTAL is active the knob moves the marker along the x axis When MOVE MKR VERTICAL is active the knob moves the marker along the y axis You can also position the limit marker by entering a discrete value for MOVE MKR HORIZNTAL with the number keys The unit for horizontal values is hertz Hz When you are ready to anchor a segment endpoint at the position of the limit marker just press START SEGMENT or FINISH SEGMENT J MOVE MKR VERTICAL softkey Key Path Marker Fctn gt LIMIT TEST gt DEFINE UPPER LIM or Marker Fetn gt LIMIT TEST gt DEFINE LOWER LIM Press MOVE MKR VERTICAL when you want to move the limit marker vertically Limits are defined as a series of line segments The limit marker s vertical position defines the y axis value of a segment endpoint It s easiest to position the limit marker by turning the knob When MOVE MKR VERTICAL is active the knob moves the marker along the y axis When MOVE MKR HORIZNTAL is active the knob moves the marker along the x axis You can also position the limit marker by entering a discrete value for MOVE MKR VERTICAL with the number keys Vertical values assume the amplitude unit of the current display the refe
37. bandwidth or video bandwidth 9 4 Key Reference ARM softkey ARM softkey Key Path Trigger Press the ARM softkey to enable triggering when manual arming is selected If you press ARM before the message WAITING FOR ARM is displayed in the lower left corner of the screen the key press is ignored Note The WAITING FOR ARM message is obscured when HP IB echo is turned on v AUTO CAL ON OFF softkey Key Path Spei Feta Press AUTO CAL ON OFF to enable and disable the analyzer s autocalibration function autocal Note Autocal is enabled automatically whenever you turn the analyzer on or press the y Preset hardkey When autocal is enabled the analyzer is automatically calibrated several times during the first hour of operation After the first hour it is automatically calibrated at one hour intervals When autocal is disabled the analyzer is only calibrated when you press SINGLE CAL Automatic calibrations do not interrupt narrow band zoom or noise level measurements They only start after these measurements are complete 9 5 Key Reference AUTO MEMORY softkey AUTO MEMORY softkey Key Path User Define gt UTILITIES Press AUTO MEMORY to automatically allocate stack space for your program Hint If you press MEMORY SIZE the value displayed in the resulting entry box tells you how many bytes of volatile RAM was allocated AUTO MEMOR
38. bytes Scratch option Scratch Start Line renumber 10 increment renumber 10 Start Line secure 1 End Line secure 32766 These parameters are retained in non volatile RAM so they are not affected by Preset or power up Default Disk 2 30 Controller Capability Analyzer Address Plotter Address Printer Address Front Panel Overview The Help Key The Help Key pone ao ES anar sonara a pence cani SREE The Help key provides fast easy to read information about specific instrument controls and features Using Help is particularly convenient when you need assistance and you don t have the analyzer s Getting Started Guide or Operating Manual near at hand The Help key is also a good way to learn about the analyzer or to refresh your memory if you don t use it often The help facility also has an index that lets you request information by key name or by topic 2 31 Rear Panel Overview Fuse Voltage Selector and Line connector For information about these items see the HP 35884 Performance Test Guide HP IB connector a A IR CD a En 0 Eg HP IB Connector The HP 3588A Spectrum Analyzer is compatible with the Hewlett Packard Interface Bus HP IB The HP IB is Hewlett Packard s implementation of the IEEE Standard 4882 To connect the analyzer to a compatible HP IB device use an HP IB interface cable The total allowable t
39. cross reference links These links allow you to move quickly between related topics When there is one link on a page it is highlighted When there are two or more links on a page only one is highlighted the others are underlined On pages with multiple links use the knob to select the link that interests you then press 4 to jump to the topic it references After reading the cross referenced topic just press 7 to return to the original topic If you decide to follow links to additional topics it s still easy to return to the original topic when you are done The analyzer keeps track of the last 20 topics displayed so you can retrace your path Just press 7 several times to reach the original topic 9 48 Key Reference Help hardkey You can page through a help topic by pressing 6 and 9 or by turning the knob Turn the knob clockwise to go to the next page or counter clockwise to go to the previous page If there are two or more links on a page the knob moves the highlight through the links before paging You can display the index by pressing 1 The index contains an alphabetical listing of all help topics available in the analyzer Each of these topics can be selected by turning the knob and displayed or jumped to by pressing 4 Most topics listed in the index describe the hardkeys and softkeys but some are of a more general nature These more general topics are only available via the index or link
40. default filename TRACE If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys Note When you enter a filename that already exists the original file is overwritten 0 without additional prompting 9 116 Key Reference SAVE UPPER LIM softkey SAVE UPPER LIN softkey Key Path Save Recall gt SAVE MORE Use SAVE UPPER LIM to save the upper limit line of the active trace to one of the disks The limit line is saved to the default disk unless you include a disk specifier in the filename prompt Caution The volatile RAM disk is cleared each time you turn the analyzer off Copy Y important limit files to another disk before power down or they will be lost When you save an upper limit you are prompted for a filename If the catalog is off the prompt contains a default filename U_LIM Tf the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys Note _ When you enter a filename that already exists the original file is overwritten e without additional prompting 9 117 Key Reference Save Recall hardkey Save Recall hardkey The softkeys grouped under Save Recail are used to load traces into the analyzer s data registers and to save and recall the following kinds of files Traces Instrume
41. displays both traces using two half height trace boxes Trace A is displayed in the upper box m FRONT BACK displays both traces using one full height trace box The active trace is drawn with a solid line the inactive trace with a dotted line m SETUP STATE summarizes the current state of the most important measurement setup parameters Use this display and one of the plot or print softkeys to document the instrument setup for a particular measurement DISPLAY FORMAT softkey Key Path User Define DISPLAY FORMAT displays a menu You can use the softkeys in the menu to do the following things m Specify the portion of the analyzer s display to be used for HP Instrument BASIC program output Clear the portion of the display that is being used for program output Dx softkeys Key Path Trace Data gt DATA REG D1 D8 Press one of the Dx softkeys to display the contents of the corresponding data register You can use options under the SAVE TRACE and RECALL TRACE softkeys to load any data register You can use SAVE NORM REFERENCE to load D8 DOTTED softkey See LINE TYPE softkeys 9 29 Key Reference ECHO ON OFF softkey ECHO ON OFF softkey Key Path Local HP 1B Press this softkey to enable and disable the echoing display of TMSL command mnemonics to the analyzer s screen TMSL mnemonics are used to operate the analyzer via the HP IB With echoing turned on you can ope
42. function as the active controller The current active controller must simply pass control to the analyzer HP IB overview HP IB the Hewlett Packard interface bus allows you to build an integrated test system from individual devices instruments and computers If a device complies with the IEEE 488 1 standard HP IB cables can link it into a system The HP 3588A is such a device Each device is assigned a unique HP IB address This allows one device referred to as the controller to coordinate the activities of all other devices on the bus The controller can issue an instruction to a particular device by prefacing the instruction with the device s address 9 50 Key Reference HP 1B TRIGGER softkey HP IB TRIGGER softkey Key Path Trigger Press HP IB TRIGGER when you must synchronize a measurement to a trigger command issued via the HP IB The HP IB connector on the analyzer s rear panel must first be connected to the controller that issues the trigger command HP 3588A Rear Panel a os Ge SEE HP 8 Connector SSee aa To Controller Once the analyzer has been armed it is triggered by one of three HP IB commands Group Execute Trigger GET a TRG a TRIG IMM Line After the analyzer has been triggered additional HP IB trigger commands are ignored until the measurement is complete and the analyzer is re armed The controller can detect these conditions _ by reading the analyzer s status
43. internal 10 MHz reference until the oven reference is warmed up Rear Panel Overview Reference Output REF OUT Reference Output REF OUT Reference Output The analyzer s 10 MHz internal reference is available at this connector This is a 3 dBm signal nominal at 509 If you connect the REF OUT signal on one analyzer to the EXT REF IN connector on another HP 35884 analyzer the second analyzer s internal 10 MHz reference will be locked to the first analyzer s 10 MHz reference A third analyzer can be locked to the second analyzer and so forth This arrangement is useful if the first analyzer contains an optional temperature controlled 10 MHz reference or is locked to an external frequency standard To minimize phase noise do not connect more than several analyzers together in this manner If it s necessary to synchronize more than several analyzers you should use an external frequency standard in conjunction with a central distribution network 3 6 Rear Panel Overview External Trigger input EXT TRIG External Trigger Input EXT TRIG External Trigger Input This input lets you synchronize a measurement with an external device If you ve selected the external trigger mode using the Trigger hardkey the analyzer will begin a measurement when the external trigger line goes low TTL level signals A trigger also occurs when you short the center pin to ground the shell of the EXT TRIG connector If yo
44. let you request additional line types that may be supported by your plotter Press USER LINE TYPE to enter the encoded value that requests a particular line type Press USER DEFINED to activate the user line type Line type changes apply only to trace A if you pressed TRACE A LINE TYPE to display these softkeys They apply only to trace B if you pressed TRACE B LINE TYPE 9 59 Key Reference LINEAR MAGNITUDE softkey LINEAR MAGNITUDE softkey Key Path gt Trace Type Press the LINEAR MAGNITUDE softkey when you want to display linear magnitude on the y axis versus frequency or time on the x axis X axis units for this coordinate system are seconds when zero span is selected They are Hz at all other times Y axis units are Vrms when you are displaying an input spectrum LINES ON OFF softkey Key Path Marker Fetn gt LIMIT TEST Press LINES ON OFF to enable and disable the display of limit lines for the active trace Note The analyzer can evaluate a trace against the current limits even when limit lines are y not displayed Just toggle TEST EVAL ON OFF to ON 9 60 Key Reference Local HP IB hardkey Local HP IB hardkey Press the Local HP 18 hardkey for one of the following reasons m To gain access to softkeys that define the analyzer s HP IB parameters To return the analyzer to local control when it is being operated via the HP IB s To abort
45. lines of 40 characters each to display variables Those containing more than 400 characters are truncated 9 35 Key Reference EXTERNAL TRIGGER softkey EXTERNAL TRIGGER softkey Key Path Trigger Press EXTERNAL TRIGGER when you must synchronize a measurement to an external trigger signal Connect a trigger source one that provides a TTL level signal to the EXT TRIG connector on the analyzer s rear panel To Trigger Source Ace Ga Karit tol a a CID A E O C pa Line S amp BEE HP WB Connector Gr PR HP 3588A Rear Panel Once the analyzer has been armed it is triggered by a high to low transition of the external trigger signal It is triggered by the falling edge of the transition After the analyzer has been triggered additional transitions of the external trigger signal are ignored until the measurement is complete and the analyzer is re armed Note A measurement consists of a single data update one sweep one FFT or one y update of the manual frequency 9 36 Key Reference FAIL BEEP ON OFF softkey FAIL BEEP ON OFF softkey Key Path Marker Fetn gt LIMIT TEST Press FAIL BEEP ON OFF to enable and disable the limit fail beeper for the active trace The limit fail beeper emits an audible tone when all of the following conditions are met FAIL BEEP ON OFF is toggled to ON BEEPER ON OFF is toggled to ON TEST EVAL ON OFF is toggled to
46. maintained in a limit register These segments need not be joined at their endpoints Each segment s amplitude values assume the current display unit the unit used for the reference level Hint You can create a limit from a trace Just save the trace with SAVE TRACE then recall it with RECALL UPPER LIM or RECALL LOWER LIM 9 58 Key Reference Limit Type softkey group Limit Type softkey group Key Path Marker Fetn gt LIMIT TEST The two softkeys in this group determine how upper and lower limits will respond when you change the reference level setting When you select ABSOLUTE LIMIT the absolute y axis value of the limit lines is held constant when the reference level changes The effect on the analyzer s screen is that the lines move when you change the reference level When you select RELATIVE LIMIT the y axis offset between the limit lines and the reference level is held constant when the reference level changes In this case the lines don t move when you change the reference level LINE TYPE softkeys Key Path Plot Print gt DEFINE PLOT gt TRACE A LINE TYPE or Plot Print gt DEFINE PLOT gt TRACE B LINE TYPE The line type softkeys let you specify the line pattern that will be used to plot each of the analyzer s two traces Three softkeys provide the most commonly selected line types w SOLID DOTTED DASHED Two more softkeys
47. manual frequency below the current span the analyzer sets the manual frequency to the span s start frequency Conversely if you specify a manual frequency above the current span the analyzer sets the manual frequency to the span s stop frequency The sample time is important for averaged measurements When making averaged measurements you should set the sample time greater than 1 RBW This ensures independent samples for each measurement and provides more accurate noise averaging Manual Sweep The Manual Measurement Point The Manual Measurement Point The manual measurement point is the display point one of 401 points that represents the current manual frequency As you change the manual frequency the manual measurement point changes When you toggle to manual sweeping the analyzer stops updating the measurement trace for all display points except the manual measurement point If the amplitude of the manual frequency changes slightly the manual measurement point wiggles To learn more about display points see chapter 4 Swept Spectrum Measurements Stepping the Manual Frequency You can step the manual frequency to quickly measure equally spaced signals over a wide span Using manual sweep lets you use a narrow resolution bandwidth to lower the noise floor thus maximizing the dynamic range This lets you make a measurement much faster than you could using the analyzer s automatic sweep Use the following sa
48. of the main marker in the active trace Here s how ZERO OFFSET works in some special cases m When the frequency counter is on the analyzer uses the measured frequency at the main marker for the x value of the offset marker a When the noise level measurement is enabled the analyzer uses the measured noise level at the main marker for the y value of the offset marker If the offset marker isn t already on it is turned on automatically when you press ZERO OFFSET 9 146 Key Reference ZERO SPAN softkey ZERO SPAN softkey Key Path Freq Use ZERO SPAN to observe modulation of a signal When you press ZERO SPAN the analyzer acts as a fixed tuned receiver You tune the receiver with CENTER Note ZERO SPAN is only available for swept spectrum measurements 4 Modulating frequencies greater than one half of the current RES BW setting are attenuated more than 3 dB These frequencies fall outside the passband of the resolution bandwidth filter Zero span can be especially useful for the following tasks 5 Observing the amplitude modulation of a carrier frequency Checking for long term amplitude instabilities in a fixed sine source m Adjusting a filter network to pass or stop a particular frequency m Matching an oscillator frequency to a reference by adjusting the beat frequency to 0 Hz zoom defined The term zoom or zooming is used to describe the process of narrowing the frequen
49. of the noise floor This is especially important when you are measuring low frequency noise or phase noise Key Reference NOISE LVL ON OFF softkey Noise level is expressed as the amount of power in a 1 Hz bandwidth for a logarithmic magnitude trace The unit is dBm Hz Noise level is expressed as the rms noise voltage in a 1 Hz bandwidth for a linear magnitude trace The unit is V rt Hz volts per square root of hertz The noise level marker only measures noise in the current input spectrum If you select trace data that is not linked to the input spectrum for example the contents of a data register no noise value is displayed If you select trace data that is linked to the input spectrum either a normalized spectrum or a math function that uses an input spectrum the noise level marker is still available However the noise level reading is not corrected to reflect the normalization or the math operations 9 76 Key Reference NON VOL RAM DISK softkey NON VOL RAM DISK softkey Key Path Save Recall gt DEFAULT DISK or Disk Util gt DEFAULT DISK Press NONVOL RAM DISK when you want to use some of the analyzer s battery backed RAM as the default disk The contents of the non volatile RAM disk are retained when you turn the analyzer off They will be available when you turn it back on The non volatile RAM disk is initialized at the factory with approximately 63 kilobytes of storage s
50. of the prompts You must increase the size of the destination disk if it isn t large enough to accept the contents of the source disk You do this by reformatting the destination disk using a different format option Copy File softkeys Key Path Disk util copy file just displays a menu The menu contains all the softkeys you need to create a new copy of a file a SOURCE FILENAME prompts you for the name of the file you want to copy m DESTIN FILENAME prompts you for the name you want to give the new copy m PERFORM FILE COPY creates a new copy of a file based on your entries in the two filename prompts Source and destination files are assumed to be on the default disk unless you precede filenames with disk specifiers Use specifiers when you want to copy from one disk to another Hint To copy all files from one disk to another use the COPY DISK softkeys When a filename prompt is displayed it already contains a name If the catalog is off the prompt contains the filename last entered If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys 9 17 Key Reference COUPLE TO INPUT Z COUPLE TO INPUT Z See Output Impedance softkey group DASHED softkey See LINE TYPE softkeys DATA REG D1 D8 softkey Math Key Path Math gt DEFINE Fx When you are defining a function pre
51. registers For more information about HP IB triggering see the HP 3588A HP IB Programming Reference 9 51 Key Reference HP instrument BASIC edit menu HP Instrument BASIC edit menu The HP Instrument BASIC edit menu and its submenus provide access to special characters and editing functions when the analyzer is in the HP Instrument BASIC edit mode enter accepts any changes you have made to the current line END EDIT exits the HP Instrument BASIC edit mode and displays the User Define menu Three softkeys INSERT LINE DELETE LINE and RECALL LINE allow you to reorganize your program one line at a time Another line oriented softkey GOTO LINE lets you move the text cursor quickly to a particular line number or program label There are two character oriented softkeys INSERT SPACE inserts a space character to the left of the text cursor DELETE CHARACTER deletes the character under the text cursor The TYPING UTILITIES softkey displays a menu that gives you access to additional characters HP Instrument BASIC keywords and a case shifting function The menu also contains a CANCEL RETURN softkey so you can return to the main editing menu inactive softkeys Some softkeys are inactive for particular analyzer setups For example RES BW is inactive during narrow band zoom measurements This is because RES BW only controls measurement resolution for swept spectrum measurements The
52. resolution bandwidth or video bandwidth setting the analyzer remembers the adjustment you made and uses this adjustment when calculating appropriate resolution or video bandwidths for different spans For example if you changed to a narrower resolution bandwidth than the default RBW the one selected automatically the analyzer maintains a narrower than normal resolution bandwidth for subsequent spans To reset the resolution bandwidth coupling to the analyzer s original settings press BW COUPLE PRESET This lets you preset bandwidth coupling without having to press Preset and losing your current setup state in the process 4 5 Swept Spectrum Measurements Bandwidth Coupling Swept Spectrum Measurements Bandwidth Coupling Swept Spectrum Measurements Bandwidth Coupling 4 8 Swept Spectrum Measurements Bandwidth Coupling Turning Off Bandwidth Coupling If you want to turn off bandwidth coupling press Res BW and toggle to BW COUPLE ON OFF Ji When you turn off bandwidth coupling you must manually set appropriate resolution bandwidth and video bandwidth settings to make useful measurements Keep in mind that when bandwidth coupling is off you must be careful not to use too fast a sweep time for the current combination of resolution bandwidth and frequency span If you do so the UNCAL status indicator appears This indicates an uncalibrated sweep this reminds you that the analyzer is sweeping too fast
53. setting your own step size is particularly useful just before you step through center frequency or manual frequency As you ll see in a moment setting your own step size makes it easy to locate harmonics of a test signal To learn about step size and manual sweep measurements see chapter 8 Manual Sweep Locating signals quickly by stepping CENTER FREQUENCY For measurements with relatively small spans it s often necessary to quickly move to a different center frequency outside the current span For example suppose you re using a narrow span to look at close in modulation products of a test signal If you wanted to look for similar modulation products for a harmonic of this test signal you could manually enter a different center frequency But there s a much faster and more accurate way by setting your own step size If you re looking at harmonics you can use the frequency counter to more accurately characterize the fundamental frequency The lets you locate the harmonics easier particularly for narrow band zoom measurements by stepping though different center frequencies Use the following sample task to discover this useful measurement enhancement 7 7 Measurement Enhancements Modifying the Step Size SAMPLE TASK Modifying step size to position the center frequency This task demonstrates how to set step size to quickly change the center frequency This method is useful for both swept spectrum and narrow band
54. softkeys in the operand menu or one of its submenus SPECTRUM selects calibrated input data as an operand SQRT NBW selects the square root of the noise equivalent bandwidth as an operand DATA REG D1 D8 CONSTANT K1 K5 and FUNCTION F1 F5 all display submenus for selecting the contents of a particular register as an operand Use the opening parenthesis softkey and the closing parenthesis softkey available in the operator menu to specify the order in which operations should be performed CANCEL RETURN is used to abandon the function definition you are creating in favor of the one that already exists 9 82 Key Reference Operator menu Operator menu Key Path Math gt DEFINE Fx gt Operator menu You specify which math operations a function will perform by pressing the softkeys in the Operator menu The following operations are available addition subtraction multiplication and division Note The analyzer does some limited tracking of units in trace math operations 4 The closing parenthesis softkey is used in conjunction with the opening parenthesis softkey available in the Operand menu to specify the order in which operations should be performed ENTER completes a new function definition If you have used fewer closing parentheses than opening parentheses ENTER adds enough to create a balance CANCEL RETURN i
55. the analyzer changes to a less sensitive input range If the input signal decreases enough to compromise the dynamic range of the current measurement the analyzer changes to a more sensitive input range When autoranging occurs you ll see an AUTORANGE IN PROGRESS message on the screen You can also request an autorange operation at any time simply press the SINGLE AUTORANGE softkey Autoranging does not have to be on for this single autorange to occur If the currently selected range is adequate for the current input signal the analyzer performs an autorange procedure but does not change the current range Because the 1 MQ input impedance is limited to one input range autoranging is inactive if you select the 1 MQ input impedance 2 2 Front Panel Overview input Input Over Range RNG Over range occurs when the input signal exceeds the currently selected input range but does not overload the analog to digital converter in the analyzer s final IF stage If this happens the RNG status indicator appears at the lower right hand corner of the screen When autoranging is on an over range condition simply causes the analyzer to change to a less sensitive input range unless the maximum input range is already selected If autoranging is off the analyzer does not change to a less sensitive range Over range lets you know that your measurement data may be questionable since the input signal is high enough to cause ga
56. through each harmonic 14 Use the arrow keys to return the manual frequency to the fundamental Now press Marker ZERO OFFSET 15 Press Sweep Again use the arrow keys to step through each harmonic Key Reference How to use this chapter This chapter contains the same information as the analyzer s on line help facility Like on line help there are definitions here for both hardkeys and softkeys and information about more general topics Also included are softkeys that appear when your instrument is equipped with the HP Instrument BASIC option This chapter is arranged alphabetically To find an individual hardkey or softkey simply use this chapter as you would a dictionary The topic entries are also arranged alphabetically and are mixed with the hardkey and softkey entries If you don t know the name of a hardkey a softkey or a topic entry use the index at the back of this book The index is where you should go to locate information by concept The index also guides you to related information in the first eight chapters of this book Key Reference ABORT HP IB softkey AA AA IA Key Reference ABORT HP IB softkey Key Path Local HP 1B Press ABORT HP IB to halt any HP IB activity initiated by the analyzer ABORT PLOT PRNT softkey Key Path Piot Print Press ABORT PLOT PRNT to stops the current plot or print operation before it is completed Active Trace har
57. to ensure an accurate measurement Swept Spectrum Measurements Sweep Time Sweep Time Sweep time is the time required for the analyzer to complete one full sweep on the display Normally sweep time is adjusted automatically The analyzer selects an appropriate sweep time based on the frequency span and the resolution bandwidth you have selected You can also set the sweep time manually Simply press Sweep and SWEEP TIME J then enter a value for sweep time If you select a sweep time that s too fast for the current frequency span and resolution bandwidth settings the UNCAL status message appears in the lower right hand corner of the display This indicates that the analyzer is sweeping too fast to make an accurate measurement On some spectrum analyzers sweep time is called scan time Also sweep time is sometimes expressed as sweep speed or sweep rate expressed either in hertz second or time graticule division Note When the analyzer s peak detector is on increasing the sweep time can cause apparent increases in the noise floor level assuming you hold the span and resolution bandwidth constant With longer sweep times the analyzer spends more time detecting peaks for a given display point This increases the chance that a larger peak will be detected if the frequencies represented by the display point contain only noise energy l To learn more about the peak detector and its function see The
58. to track the peak the component with the largest amplitude in the current measurement span To turn on signal track press Freq and then toggle to SIGNL TRK ON OFF The effect of signal track is similar to the effect you would get by continuously pressing MKR PEAK and then MKR CTR FREQ The difference of course is that the analyzer can do this quickly enough to ensure that signal track occurs once for each measurement Special considerations m In order for the analyzer to track a drifting signal drift must be less than the current span divided by the sweep time u Signal track is not available for manual sweeps 7 6 Measurement Enhancements Modifying the Step Size Modifying the Step Size If you press Freg you will see the STEP SIZE AUTO USER and USER STEP SIZE softkeys These two softkeys are very useful since you can use them to select your own step size This makes it much easier and faster to perform certain measurements especially if you use the frequency counter to more accurately set the step size As we mentioned in chapter 2 step size controls the sensitivity of both the knob and the arrow keys By sensitivity we mean the interval between each numeric entry as you turn the knob You can modify the default step size to better select the following parameters Center frequency Start frequency Stop frequency Manual frequency Toggling to STEP SIZE AUTO USER and then
59. trace math disk catalog 9 12 default 9 20 delete disk option 2 9 format options 9 39 formatting 9 38 9 88 interleave factor 9 56 internal 2 9 9 55 non volatile 9 77 packing 9 85 specifiers 9 27 utilities 9 27 volatile 9 146 volume name 9 146 disk copying See copy operations display active trace 2 15 annotation blanking 9 9 autoscaling 9 6 blanking 9 9 CRT care and cleaning 2 19 display resolution 4 11 fonts used 9 38 format options 9 29 graticule 9 46 mini state 2 12 pop up message area 2 16 reference level 9 108 reference level tracking 9 107 Status indicator area 2 14 Status message area 2 18 trace boxes 2 15 trace title 2 18 9 139 x axis notation 2 17 y axis notation 2 16 display keys 2 25 display resolution 9 43 See also frequency resolution and display resolution E entry down key See arrow keys entry up key See arrow keys EXT REF IN See external reference input EXT TRIG See external trigger input external reference input 3 4 external trigger 9 36 external trigger input 3 7 index Continued F FFT measurements See narrow band zoom measurements file copying See copy operations files deleting all 9 25 deleting individual 9 26 formatting See disk frequency counter 6 6 9 41 for numeric entry 6 6 frequency resolution and display resolution 4 12 frequency span 9 127 start and stop 9 129 frequency span full 9 44 frequency step size 9 131 H hardkeys 1 2 2 11 9 47 help key 2 31 9 4
60. zoom measurements In the example here we ll examine a test signal and its harmonics 1 Press Preset 2 Connect the signal source to the analyzer s input 3 Press Marker MKR gt PEAK 4 Press Marker Fetn Then toggle to FREQ CNTR ON OFF J 5 Press Marker MKR gt CTR FREQ 6 Press Meas Type NARROW BAND ZOOM 7 8 Measurement Enhancements Modifying the Step Size 7 Press Freq Toggle to STEP SIZE AUTO USER Press USER STEP SIZE Marker Value 8 If you need to you can press SPAN and use the knob or the arrow keys to move to a smaller frequency span 9 Press CENTER Now press use the arrow keys to step to the test signal s harmonics Measurement Enhancements Low distortion mode Low distortion mode Overview All spectrum analyzers introduce low level distortion products to the signals they are measuring the relative level of these products varies but all analyzers introduce them Since these distortion products are very low you can ignore them in many measurement situations However the distortion contribution of an analyzer becomes important when you are measuring spectral components that are within 10 dB of the analyzer s published distortion specifications In these measurement situations using low distortion mode can improve your measurement results What does it do Low distortion mode automatically conf
61. 00 9 43 Key Reference FRONT BACK softkey For narrow band zoom measurements a display point represents all frequencies between NF 1 2 PBW and NF 1 2 PBW NF is the nominal frequency and PBW is the point bandwidth CT frequency span A 1 2 point BW ES start siop freq freq le Point 0 Point 1 Point 2 0000 Poimt 400 FRONT BACK softkey See Display Format softkey group trace FULL SPAN softkey Key Path Freq The FULL SPAN softkey gives you a quick way to set the analyzer to its widest frequency span for the current measurement type s 40kHz for narrow band zoom a 150 MHz for swept spectrum FULL SPAN doesn t change the center frequency CF for narrow band zoom However it resets CF to 75 MHz for swept spectrum so the sweep will start at 0 Hz Use FULL SPAN and a swept spectrum measurement to locate a signal You can then narrow the span with CENTER and SPAN or START and STOP for more detailed analysis At spans less than 40 kHz use narrow band zoom for shorter measurement times 9 44 Key Reference FUNCTION F1 F5 softkey Math FUNCTION F1 F5 softkey Math Key Path Math gt DEFINE Fx When you are defining a function press FUNCTION F1 F5 to gain access to the FUNCTION Fx softkeys These softkeys let you specify the contents of other function registers as operands in the function you are defining See also Operand Menu
62. 8 high accuracy zoom See narrow band zoom measurements high resolution zoom See narrow band zoom measurements HP Instrument BASIC automemory 9 6 debug utility 9 19 deleting characters 9 25 deleting lines 9 26 display format 9 28 editing 9 31 9 46 9 52 9 54 keystroke recording 9 32 memory size 9 70 program stepping 9 123 re saving programs 9 103 renumbering lines 9 88 scratch options 9 119 securing programs 9 33 9 120 utilities 9 142 variables 9 35 HP IB 9 50 9 61 connector 3 1 controllers 9 50 mnemonic echo 9 30 trigger 9 51 user SRQ 9 141 input 2 1 input trip 2 4 over range 2 3 overload 2 3 input autoranging See autoranging input impedance 1 Megohm 2 5 50 ohm 2 4 75 ohm 2 4 input levels maximum allowable 2 4 maximum for each range 2 2 K knob the 2 20 L limit testing 6 10 9 58 beeper 9 37 limits absolute 6 10 relative 6 10 local oscillator feedthrough 4 2 local HP IB See controller capability low distortion mode 7 10 9 63 M main marker 6 1 marker to center frequency 6 4 9 71 marker to peak 6 3 9 71 marker to reference level 9 72 next left peak 6 3 9 80 next right peak 6 3 9 80 See also offset marker peak track 6 5 manual frequency See manual sweep manual frequency stepping See step size manual sweep 4 14 8 1 9 132 manual frequency 8 2 9 64 manual measurement point 8 4 sample time 8 2 special considerations 8 3 marker See main marker marker readout 2 13 marker value 9 67
63. 9 9 Key Reference BW COUPLE ON OFF softkey BW COUPLE ON OFF softkey Key Path Res BW Press BW COUPLE ON OFF to enable and disable bandwidth coupling When bandwidth coupling is on the analyzer automatically adjusts the resolution bandwidth video bandwidth and sweep time when you change the frequency span Note Bandwidth coupling is not active during narrow band zoom measurements y The order of dependency among coupled parameters from least dependent to most follows Span gt Resolution BW gt Video BW gt Sweep Time Span is completely unaffected when another coupled parameter changes Sweep time is affected when any other coupled parameter changes Note Video bandwidth is always coupled to resolution bandwidth even when coupling is w turned off If you change the value of a dependent parameter a new relationship is established between that parameter and the one that precedes it in the dependency chain If bandwidth coupling is on the analyzer attempts to maintain the new relationship when the less dependent parameter changes For example if you select a narrower than normal resolution bandwidth for the current span the analyzer automatically selects a narrower than normal resolution bandwidth for all subsequent spans Hint You can return the coupled parameters to their default relationships by pressing the BW COUPLE PRESET softkey 9 10 Key Reference BW COUPLE PRESET s
64. AMPLITUDE STEP softkey Key Path Source Use AMPLITUDE STEP to define the effect of the knob and arrow keys on the value of SOURCE AMPLITUDE You are prompted to define the effect in dB of amplitude change The value of AMPLITUDE STEP determines the smallest amplitude change possible when you turn the knob slowly It also determines the amplitude change that results when you press an arrow key once ANALYZER ADDRESS softkey Key Path Local HP IB Press this softkey when you want to change the analyzer s HP IB address A prompt is displayed so you can enter the new address Note The analyzer s address is saved in non volatile memory so it is retained when you e turn the analyzer off and on The range of valid addresses for the analyzer includes all integer values from 0 through 30 ARM AUTO MAN softkey Key Path Trigger Press this softkey to toggle between automatic and manual arming of the analyzer s triggering system The analyzer s hardware must settle before the triggering system can be armed If you select automatic arming the analyzer arms itself immediately after settling If you select manual arming the analyzer pauses after settling and waits for you to arm the trigger with the ARM softkey Hardware settling occurs each time you change the frequency span and for swept spectrum measurements each time a new sweep begins Settling time increases when you decrease the span resolution
65. CTRUM when you plan to use the HP 35884 as a traditional swept tuned spectrum analyzer i During swept spectrum measurements the analyzer gathers frequency domain measurement data by mixing your input signal with a sweeping local oscillator LO and then detecting the difference frequency The analyzer s display appears to sweep through the band of frequencies you have specified Swept spectrum measurements offer several measurement options that are not available during narrow band zoom measurements w Wider spans up to 150 MHz Manual sweeping Zero span analysis Noise level markers However narrow band zoom measurements provide much shorter measurement times at spans below 40 kHz Note You can control the frequency resolution of swept spectrum measurements with the g RES BW softkey The analyzer maintains the current center frequency when you change from swept spectrum to narrow band zoom measurements However it selects a new span from the 16 available in narrow band zoom according to the following rules m Ifthe current span is greater than or equal to 40 kHz you get a 40 kHz span Ifthe current span is less than 40 kHz you get the closest available span that is greater than or equal to the current span The analyzer also maintains the current center frequency when you change from narrow band zoom to swept spectrum measurements But in this case it restores the span from the previous swept sp
66. Data Press SAVE NORM REFERENCE to save the contents of the active trace to data register D8 Calibrated input data the data displayed when you press INPUT SPECTRUM is divided by the contents of D8 to create a normalized spectrum SAVE PROGRAM softkey Key Path Save Recall gt SAVE MORE When you create a new HP Instrument BASIC program use SAVE PROGRAM to save it for the first time Saving a program with this softkey protects you from accidently overwriting a file with the same name Then to save changes you make while editing the program use RE SAVE PROGRAM Both softkeys save your program to the default disk unless you include a disk specifier in the filename prompt _ _ _ _ ___ _ Caution The volatile RAM disk is cleared each time you turn the analyzer off Copy important programs to another disk before power down or they will be lost qA_ _ _____Q When you save a program you are prompted for a filename If the catalog is off the prompt contains a default filename either PROG or the name of the last program you saved or recalled If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys 9 114 Key Reference SAVE STATE softkey SAVE STATE softkey Key Path Save Recall Use SAVE STATE to save the current instrument state to one of the disks The state i
67. EST gt DEFINE LOWER LIM Limits are defined as a series of line segments Press START SEGMENT to anchor a segment s starting point at the position of the limit marker Press FINISH SEGMENT to anchor a segment s ending point Use MOVE MKR HORIZNTAL and MOVE MKR VERTICAL to position the limit marker 9 130 Key Reference STEP SIZE AUTO USER softkey STEP SIZE AUTO USER softkey Key Path Freg Press this softkey to toggle between the analyzer determined AUTO and user determined USER step size for the following frequency parameters m CENTER START STOP m MANUAL FREQ When you change the value of these parameters step size determines the effect of the knob and arrow keys x For the knob it determines the smallest frequency change possible when you turn the knob slowly a For the arrow keys it determines the frequency change that results when you press an arrow key once If you toggle to USER step size is defined with the USER STEP SIZE softkey If you toggle to AUTO step size is defined by the following formulas For CENTER SPAN 400 For START and STOP SPAN 10 m For MANUAL FREQ the smaller of the following RES BW 1 30 or SPAN 400 m For CENTER START and STOP in zero span RES BW 10 9 131 Key Reference SWEEP AUTO MAN softkey SWEEP AUTO MAN softkey Key Path Sweep Press this softkey to toggle betw
68. F softkey Key Path Res BW Press VID FLTR ON OFF to enable and disable the analyzer s video filter The video filter has a display smoothing function It reduces noise variance so you can see signals that are close to the noise floor You adjust the video filter s bandwidth to control the degree of smoothing Note You can also use video averaging to reduce noise variance 4 You can t use the video filter for narrow band zoom measurements 9 143 Key Reference VIDEO AVERAGE softkey VIDEO AVERAGE softkey Key Path Avg Pk Hid Press this softkey to enable video averaging an rms power averaging function that combines the results of several measurements Video averaging reduces noise variance so you can see signals that are close to the noise floor When video average is selected the results of a completed measurement are combined point by point with the previous input spectrum The combined results are retained and displayed as the updated input spectrum The analyzer uses this formula to combine data 1 N new N 1 N old N is a weighting factor that you specify under the NUMBER AVERAGES softkey As the formula indicates new data is weighted more heavily than old data once the analyzer has averaged the results of N measurements Averaging that combines data in this manner is often referred to as exponential averaging Note The analyzer does not stop measuring after N meas
69. GHT PEAK NXT LEFT PEAK OFFST MKR gt SPAN OFFSET ON OFF MARKER ON OFF Marker Fetn hardkey PEAK TRK ON OFF J FREQ CNTR ON OFF J NOISE LVL ON OFF LIMIT TEST LINES ON OFF TEST EVAL ON OFF FAIL BEEP ON OFF ABSOLUTE LIMIT RELATIVE LIMIT DEFINE UPPER LIM MOVE MKR HORIZNTAL MOVE MKR VERTICAL START SEGMENT FINISH SEGMENT MOVE ALL VERTICAL DELETE ALL DELETE SEGMENT DEFINE LOWER LIM 10 5 Menu Map System Group System Group Preset hardkey User Define hardkey RUN CONTINUE EDIT ENTER INSERT SPACE INSERT LINE DELETE LINE RECALL LINE DELETE CHARACTER TYPING UTILITIES ENTER INSERT SPACE INSERT KEYWORD DELETE CHARACTER UPPERCASE lowercase INSERT INSERT amp INSERT lt gt JN INSERT 1 GOTO LINE ENTER iy UPPERCASE lowercase END EDIT PRINT PROGRAM 10 6 User Define hardkey continued UTILITIES MEMORY SIZE AUTO MEMORY SCRATCH SCRATCH SCRATCH SCRATCH A PERFORM SCRATCH RENUMBER START LINE INCREMENT PERFORM RENUMBER SECURE START LINE END LINE PERFORM SECURE ENABLE RECORDING DEBUG RUN CONTINUE SINGLE STEP LAST ERROR EXAMINE VARIABLE RESET DISPLAY FORMAT OFF FULL UPPER LOWE
70. HP 3588A Operating Manual This Operating Manual is a subset of the the HP 3588A Operating Manual Set HP Part Number 03588 90000 CA prexano Printed in U S A Print Date March 1990 Hewlett Packard Company 1990 All rights reserved 8600 Soper Hill Road Everett Washington 98205 1298 LA erciano SAFETY SUMMARY The following general safety precautions must be observed during all phases of operation service and repair of this instrument Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the instrument Hewlett Packard Company assumes no liability for the customers failure to comply with these requirements This is a Safety Class 1 instrument GROUND THE INSTRUMENT To minimize shock hazard the instrument chassis and cabinet must be connected to an electrical ground The instrument is equipped with a three conductor ac power cable The power cable must either be plugged into an approved three contact electrical outlet or used with a three contact to two contact adapter with the grounding wire green firmly connected to an electrical ground safety ground at the power outlet The power jack and mating plug of the power cable meet International Electrotechnical Commission IEC safety standards DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE Do not operate the instrument in the presence of flammable gases or fumes Operation o
71. IMIT TEST gt DEFINE UPPER LIM or Marker Fetn gt LIMIT TEST gt DEFINE LOWER LIM Press DELETE ALL to delete an entire limit This softkey deletes the active trace s upper limit if you pressed DEFINE UPPER LIM to enter the menu It deletes the active trace s lower limit if you pressed DEFINE LOWER LIM to enter the menu DELETE CHARACTER softkey Press this softkey to delete the character under the text cursor during alpha entry or program editing Hint Use the knob to place the text cursor over the character you want to delete 9 25 Key Reference DELETE FILE softkey DELETE FILE softkey Key Path Disk Util Press DELETE FILE to remove a file from one of the disks The file is deleted from the default disk unless you include a disk specifier in the filename prompt Hint To remove all files from a disk at once use the DELETE ALL FILES softkey It s often easier to delete files when the catalog is on You can select the file you want to delete by turning the knob Then when you press DELETE FILE the name of the selected file is automatically placed in the prompt When the catalog is off the last entered filename is place in the prompt You can modify the name in the prompt with the alpha entry keys Note When you press the ENTER softkey to complete entry of a filename the file is yi deleted without further prompting Be sure the name is correct before pressing
72. INE UPPER LIM gt DELETE ALL or Marker Fetn gt LIMIT TEST gt DEFINE LOWER LIM gt DELETE ALL Press this softkey to confirm your intention to delete a limit CONSTANT K1 K5 softkey Math Key Path Math gt DEFINE Fx When you are defining a function press CONSTANT K1 K5 to gain access to the CONSTANT Kx softkeys These softkeys let you specify the contents of corresponding constant registers as function operands See also Operand Menu CONSTANT K1 K5 softkey Trace Data Key Path Trace Data Press CONSTANT K1 K5 for access to the kx softkeys Each Kx key displays the magnitude of a constant you have defined Note Constants are defined under the Math hardkey Y Key Reference CONSTANT Kx softkeys CONSTANT Kx softkeys Key Path Math gt DEFINE Fx gt CONSTANT K1 K5 When you are defining a function press one of the CONSTANT Kx softkeys to specify the contents of the corresponding constant register as an operand The abbreviation Kx is added to the end of the definition CONTINUE softkey Key Path User Define or User Define gt DEBUG Press CONTINUE to resume execution of a paused program Execution resumes from the point at which the program was paused Note You can only continue a paused program However you can restart any program y from its first statement by p
73. LEAR ENTRY ENTER J Trace Type hardkey Trace data can be displayed in different coordinate systems Softkeys grouped under the Trace Type hardkey allow you to select a coordinate system for the active trace The coordinate systems offered in this analyzer are Logarithmic magnitude versus frequency or time s Linear magnitude versus frequency or time Trigger hardkey The Trigger hardkey displays a menu The softkeys in this menu allow you to synchronize an HP 3588A measurement with some external event The analyzer uses a two stage triggering system to hold off measurements The first stage of the system just arms the second enabling it to respond to a trigger event Two softkeys in the Trigger menu T arm auto man and ARM allow you to control the first stage The second stage of the triggering system is the trigger itself After it has been armed this stage of the system waits for a trigger event Three softkeys in the Trigger menu allow you to specify the nature of the trigger event FREE RUN TRIGGER m EXTERNAL TRIGGER J HP 18 TRIGGER A measurement begins when the triggering system has been armed and triggered Hint To manually trigger a single measurement one sweep one FFT or one update of the manual frequency select FREE RUN TRIGGER and toggle ARM AUTO MAN to MAN With this setup you can trigger a single measurement by pressing ARM 9 139 Key Reference
74. Marker Marker Readout Marker to peak ee s a b s s uab a ss aao Marker to next right peak Mana left peak ci Marker to center frequency Offset to span Peak Track Frequency Counter Overview Noise Level Overview Limit Testing Overview Cr o 8 Counting Behavior a s r r 0 b e gt o sba e e aas e oe sass s e 0 t gt 2 o oe 8 0 o 2 4 0 0 Special Considerations Noise Measurements and Trace Data o s 2 q 0 o e 8 Absolute and Relative Limits Introduction Chapter 7 Measurement Enhancements Scalar Network Measurements 4s o we He ee ee ew Table of Contents Continued o 2 eB RF o s gt o a oe o o e e 4 8 k a 4 2 8 amp 9 amp e 8 8 8 t a amp Be eH ew 4 2 amp BF 8 0 oe o o o s a o o o eH o 2 o o o o 6 o we o o o L 9on amp 8 amp 0 po 4 oe 8 ssp 0 a so a gt o 8 o o wie o gt a ee He e 6 Special Considerations for Scalar Network Measurements a Normalization Trace Math Overview Vide
75. NE softkey Key Path User Define gt EDIT Press RECALL LINE to recall the last line you deleted when you are editing a program A line is always recalled with its original line number You must change this number if you want the recalled line to remain at its new location when you press ENTER The new line number must fall between the line numbers of adjacent program lines Hint If you press INSERT LINE before RECALL LINE you will be able to see the line numbers of both adjacent lines RECALL LOWER LIM softkey Key Path Save Recall gt RECALL MORE Use RECALL LOWER LIM to recall a limit line into the lower limit register of the active trace The limit line is recalled from the default disk unless you include a disk specifier in the filename prompt Hint You can create a limit from a trace Just save the trace with SAVE TRACE then recall it with RECALL UPPER LIM or RECALL LOWER LIM E When you recall a lower limit you are prompted for a filename If the catalog is off the prompt contains a default filename L_LIM If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys RECALL MATH softkey Key Path Save Recall gt RECALL MORE Use RECALL MATH to recall a complete set of math definitions all functions and constants from one of the disks The definitions a
76. Note Changes made with the arrow keys and the knob take effect immediately E 9 79 Key Reference NXT LEFT PEAK softkey NXT LEFT PEAK softkey Key Path Marker Press NXT LEFT PEAK to move the main marker one peak to the left of its current location in the active trace A peak is a local maximum on a trace The slope of a trace is positive to the left of a peak and negative to the right In addition the slope on one side of a peak must not change for at least one vertical division one half division if the display format is upper lower The next left peak must be at least one display point to the left of the current marker location If the peak search algorithm doesn t find a peak the marker doesn t move Hint Decrease the value of VERTICAL DIV to increase the number of peaks found Use any of the marker search keys including NXT LEFT PEAK with offset markers to quickly measure frequency and amplitude differences between two signals NXT RIGHT PEAK softkey Key Path Marker Press NXT RIGHT PEAK to move the main marker one peak to the right of its current location in the active trace A peak is a local maximum on a trace The Slope of a trace is positive to the left of a peak and negative to the right In addition the slope on one side of a peak must not change for at least one vertical division one half division if the display format is upper lower The next right peak must
77. Peak Detector sidebar later in this chapter 4 10 Swept Spectrum Measurements Sweep Time 4 11 Swept Spectrum Measurements Sweep Time 4 12 Swept Spectrum Measurements Sweep Time 4 13 Swept Spectrum Measurements Manual Sweep Manual Sweep For swept spectrum measurements sweep times can be very long for small spans particularly when using a narrow resolution bandwidth If you press Sweep and then toggle to SWEEP AUTO MAN you can disable the analyzer s automatic sweep and enable manual sweep Manual sweep lets you tune the analyzer to a discrete frequency This lets you measure the amplitude of discrete frequencies without waiting for the analyzer to sweep through an entire span a considerable advantage when using both a narrow resolution bandwidth and a narrow video bandwidth Manual sweep is also useful when making automated measurements Using manual sweep dramatically reduces measurement time since it s much faster to transfer amplitude data for a single frequency over the HP IB rather than sending data for the entire 401 point display When using manual sweep the analyzer is in effect a fixed tuned receiver You can change the tuned frequency with the knob or by entering a discrete frequency with the numeric entry keypad You can also step through a series of discrete frequencies by setting the step size accordingly To learn more about all this see chapter 8 Manual Sweep 4 14
78. Q conversion The return loss of the source output regardless of impedance selected is greater than 20 dB You can set the source to automatically change its impedance if the input impedance setting is changed You can do this by pressing COUPLE TO INPUT Z under the source menu Front Panel Overview Source The source output is protected and can tolerate input signals of less than 4 volts peak The source circuit breaker will trip if you connect a signal that exceeds this level After removing the accidentally connected signal press Source and then CLEAR SRCE TRIP Caution Although the analyzer s source has protection circuitry the following signals Y accidentally applied to the source connector may damage the analyzer e RF signals greater than 20 dBm 509 or 22 dBm 759 e dc offsets greater than 3V e peak combined ac dc input level greater than 3 Vpeak 2 8 Front Panel Overview Disk Drive Disk Drive dl E AE ta Sa pp Goal oe 241 3372 PS bees Disk Drive The analyzer has a built in 3 5 inch flexible disk drive that you can use to load HP Instrument BASIC programs You can also use the disk drive to store traces instrument setup states limit tests math functions and HP Instrument BASIC programs Analyzers equipped with Option 004 do not have an internal disk drive The disk drive accepts the standard gray 3 5 inch 710 kilobyte double sided flexible disks for example the HP 92192A
79. R CLEAR SCREEN Menu Map System Group 10 7 Menu Map System Group Help hardkey Save Recall hardkey 10 8 SAVE TRACE INTO FILE INTO Dx SAVE STATE SAVE AUTO STATE SAVE MORE SAVE UPPER LIM SAVE LOWER LIM SAVE MATH SAVE PROGRAM RE SAVE PROGRAM CATALOG ON OFF RECALL TRACE FROM FILE INTO Dx CATALOG ON OFF RECALL STATE RECALL MORE RECALL UPPER LIM RECALL LOWER LIM RECALL MATH RECALL PROGRAM CATALOG ON OFF CATALOG ON OFF DEFAULT DISK NON VOL RAM DISK VOLATILE RAM DISK INTERNAL DISK CATALOG ON OFF Disk Util hardkey RENAME FILE ORIGINAL FILENAME NEW FILENAME PERFORM RENAME CATALOG ON OFF DELETE FILE DELETE ALL FILES COPY FILE SOURCE FILENAME DESTIN FILENAME PERFORM FILE COPY CATALOG ON OFF COPY DISK SOURCE DISK DESTIN DISK PERFORM DISK COPY CATALOG ON OFF PACK DISK FORMAT DISK FORMAT OPTION INTRLEAVE FACTOR PERFORM FORMAT CATALOG ON OFF CATALOG ON OFF DEFAULT DISK Local HP IB hardkey ABORT HP IB SYSTEM CONTROLLR ADDRESSBL ONLY ANALYZER ADDRESS PERIPHERL ADDRESSES PLOTTER ADDRESS PRINTER ADDRESS ECHO ON OFF USER SRA USER SRQ x Menu Map System Group 10 9 Menu Map System Group Plot Print hard
80. Reference TRACE A PEN softkey TRACE A PEN softkey Key Path PloyPrint gt DEFINE PLOT gt DEFINE PLOT PENS Press TRACE A PEN to specify which plotter pen should be used for plotting trace A and all of its trace specific annotation Trace specific annotation includes the following items Trace title Marker readout X axis annotation Y axis annotation Limit test results TRACE B LINE TYPE softkey Key Path Piot Print gt DEFINE PLOT Press TRACE B LINE TYPE for access to the line type softkeys The line type you specify with these softkeys will be used to plot trace B Note Check your plotter s documentation to be sure that it supports the requested Ce line type 9 137 Key Reference TRACE B PEN softkey TRACE B PEN softkey Key Path Plot Print gt DEFINE PLOT gt DEFINE PLOT PENS Press TRACE B PEN to specify which plotter pen should be used for plotting trace B and all of its trace specific annotation Trace specific annotation includes the following items Trace title Marker readout X axis annotation Y axis annotation Limit test results Trace boxes A trace box is a bounded area of the screen that is used to display trace data There are two trace box sizes full height and half height A full height trace box is used for the single and front back trace formats The graticule for this box is ten divisions high and ten division
81. START SEGMENT Press this softkey after you have defined the starting point of a segment m FINISH SEGMENT Press this softkey after you have defined the ending point of a segment 9 22 Key Reference DEFINE PLOT PENS softkey m MOVE ALL VERTICAL This lets you alter the amplitude value of all endpoints at once DELETE ALL This deletes all segments at once m DELETE SEGMENT This deletes the segment that is vertically aligned with the limit marker After you define a lower limit it is maintained in a limit register The amplitude values of the limit are maintained without units so they assume the amplitude unit of the current display the unit used for the reference level Hint You can also create a lower limit from a trace Just save the trace with SAVE TRACE then recall it with RECALL LOWER LIM DEFINE PLOT PENS softkey Key Path plot Print gt DEFINE PLOT The DEFINE PLOT PENS softkey displays a menu You use the softkeys in the menu to assign plotter pens to various items on the analyzer s screen m TRACE A PEN Used for trace A and all of its trace specific annotation TRACE B PEN Used for trace B and all of its trace specific annotation m MARKER A PEN Used for trace A s main and offset markers a MARKER B PEN Used for trace B s main and offset markers m ALPHA PEN Used for information that is not trace specific m GRATICULE PEN Used for the gratic
82. Scalar network measurements Getting Started Operating Manual Spectrum analyzer basics Getting Started 1 1 Before You Begin Hardkeys and Softkeys Before you use this book it s important to understand the difference between hardkeys and softkeys Hardkeys are front panel buttons whose functions are always the same Hardkeys have a label printed directly on the key itself Throughout this book they are printed like this Hardkey Softkeys are keys whose functions change with the analyzer s current menu selection A softkey s function is indicated by a video label to the left of the key on the edge of the analyzer s screen The companion video labels to the left of the ten softkeys form the softkey menu Throughout this book softkeys are printed like this SOFTKEY Some softkeys toggle through different settings Toggle softkeys have a highlighted word in their label that changes with each press of the softkey Throughout this book toggle softkeys are depicted as they appear after you make the keypress For example toggle to FREQ CNTR ON OFF means to press FREQ CNTR ON OFF until the word ON is highlighted Before You Begin Where to find Additional Information Where to find Additional Information Using the Heip key The Help key on the analyzer s front panel provides fast easy to read information about specific instrument controls and features Using Help is particularly convenient when yo
83. T SRCE 20dB B IN OUT J a SRCE DAC ATTEN You should only use these softkeys as directed in your HP 3588A Performance Test Guide 9 89 Key Reference PERIPHERL ADDRESSES softkey PERIPHERL ADDRESSES softkey Key Path Local HP IB Use the softkeys grouped under PERIPHERL ADDRESSES to tell the analyzer what addresses are currently assigned your HP IB peripherals The peripherals can either be plotters or printers PLOT ALL softkey Key Path Piot Print Press the PLOT ALL softkey to plot everything on the analyzer s screen except for the softkey labels PLOT ALL allows you to plot any of the following things x Traces m The instrument state m The disk catalog a Output from an HP Instrument BASIC program However it does not allow you to plot HP Instrument BASIC programs or Help screens They can only be printed You can define most plot parameters under the DEFINE PLOT softkey but you must change plot scaling parameters on the plotter itself Note Plotting is only possible if the SYSTEM CONTROLLR softkey is selected and if the y value entered under the PLOTTER ADDRESS softkey matches the setting on your plotter 9 90 Key Reference PLOT GRATICULE softkey PLOT GRATICULE softkey Key Path Plot Print Press PLOT GRATICULE to plot every graticule that is currently displayed on the analyzer s screen Graticules are always plotted with solid lines
84. Y provides a convenient way to allocate stack space for programs you develop in the analyzer or load via the HP IB If the automatically set value is not adequate use MEMORY SIZE to change it Note If you encounter the message ERROR 2 Memory overflow while your program s is running you need to allocate more stack space AUTO SCALE softkey Key Path Scale Each time you press the AUTO SCALE softkey the active trace is rescaled and repositioned vertically to provide the best display of your data Best display is determined by an autoscaling algorithm which changes the values of REFERENCE LEVEL and VERTICAL DIV The new values are used until you do one of the following Manually enter a new value for either parameter Press AUTO SCALE again Toggle reference level tracking from off to on Change the input range while reference level tracking is on 9 6 Key Reference AUTORANGE ON OFF softkey AUTORANGE ON OFF softkey Key Path Range input Press AUTORANGE ON OFF to enable and disable continuous autoranging When continuous autoranging is on the analyzer monitors the level of your input signal and selects the best input range for that signal It changes the range under these circumstances x If the signal level increases enough to overdrive the input circuitry the analyzer selects a less sensitive input range m Ifthe signal level decreases enough to compromise dynamic ra
85. a file on a disk other than the default disk For example enter INT MYCONFIG to access a file named MYCONFIG that resides on the internal disk Disk Util hardkey The softkeys grouped under Disk Util are used to perform various file and disk management operations m Renaming files Deleting files Copying files Formatting disks Packing disks Note To save and recall files use the softkeys grouped under Save Recall Y The analyzer displays a prompt and enters alpha entry mode when it s time to identify the file or disk you want to modify Use the default filename displayed in the prompt or modify the name with the alpha entry keys When the filename is correct press enter to start the operation You can do two things to simplify disk and file management Operations a Designate the disk you use most often as the default disk Display the disk catalog You only need to enter a filename to identify a file on the default disk You must enter a disk specifier and a filename to identify a file on any other disk When the catalog is displayed you don t need to type the name of a file you want to modify Instead you can just select the file with the knob before bringing up the filename prompt The name of the file you select is automatically placed in the prompt 9 27 Key Reference DESTIN DISK softkey DESTIN DISK softkey See Copy Disk softkeys DESTIN FILENAME softkey See Copy F
86. alled from the default disk unless you include a disk specifier in the filename prompt The recalled state includes math definitions The contents of the function and constant registers are overwritten by these definitions Hint If you want to recall a state and keep your current math definitions do this 1 Save the math definitions 2 Recall the state 3 Recall the math definitions you just saved When you recall a state you are prompted for a filename If the catalog is off the prompt contains a default filename STATE If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys 9 105 Key Reference RECALL TRACE softkeys RECALL TRACE softkeys Key Path Save Recall The softkeys grouped under RECALL TRACE let you load a trace into one of the analyzer s data registers The trace is recalled from the default disk unless you include a disk specifier in the filename prompt Note To display the recalled trace you must select the corresponding data register under e the Trace Data hardkey When you recall a trace you are prompted for a filename If the catalog is off the prompt contains a default filename TRACE If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys RECALL UPPER LIM softkey Key Pat
87. als OFFST MKR gt SPAN softkey Key Path Marker When you press OFFST MKR gt SPAN the analyzer s span is reset to the absolute value of the frequency difference between the main marker and the offset marker Note For narrow band zoom measurements If the offset doesn t exactly match one of E the available spans the analyzer selects the next larger span Here s how OFFST MKR gt SPAN positions the new span along the x axis For swept spectrum measurements START is set to the smaller of the two markers frequencies and STOP is set to the larger a For narrow band zoom measurements CENTER is set to main marker freq offset marker freq 2 OFFST MKR gt SPAN does nothing if the offset markers are turned off It also does nothing if zero span is selected 1 MEGOHM softkey See Input Impedance softkey group 9 81 Key Reference 1 MEG REF IMPEDANCE softkey 1 MEG REF IMPEDANCE softkey Key Path Range Input Press this softkey to change the reference impedance used in dBm calculations The analyzer only uses the reference impedance for dBm calculations when the you select the 1 megohm input impedance It uses the nominal impedance for these calculations when you select either the 50 or 75Q input impedance See also Input Impedance softkey group Operand menu Key Path Math gt DEFINE Fx You specify the data to be used in a function by pressing the
88. alyzer s analog to digital converter This message occurs when you overload the analyzer s least sensitive range 2 14 Front Panel Overview Display Area Trace Box A and Trace Box B Range 3 dBm R Trace Box A Trace Box B The analyzer has two display traces You can display these two traces several ways single one trace at a time upper lower trace A on top trace B on bottom or front back one trace overlaid on the other Each trace shows measurement data with 401 points of resolution regardless of span It s important to understand that both Trace A and Trace B are independent and are not dedicated to showing specific parameters Rather you can display one of four different types of information Input Spectrum current measurement data a Functions F1 through FS math functions Constants K1 through K5 math constants m Data Registers D1 through D8 you can save traces limits and math functions to a data register and then subsequently display them using the Trace Data hardkey m Normalized Spectrum the current input spectrum divided by a stored normalization trace One trace is active at any given time indicated by the highlighted trace title The active trace is the target of any adjustments you make with the display keys For example if you press Trace Data and press DATA REG D1 D8 to call up a stored trace the stored trace will only appear in the currently acti
89. ample softkey the state would toggle to autosweep Softkeys The analyzer has ten softkeys that are arranged in a column to the right of the screen They are referred to as softkeys because the function assigned to each key can change In contrast the function assigned to each hardkey never changes For example when you press the Source hardkey the first softkey is used to turn the analyzer s source on and off But when you press the Plot Print hardkey the first softkey is used to initiate a plot of the analyzer s screen A softkey s current meaning is determined by its softkey label The label is displayed on the screen adjacent to the softkey Also softkey labels surrounded by brackets are used to represent softkeys in help text for example The input spectrum softkey is used to Special types of softkeys include the following those that can toggle between two states those that are part of a bracketed group and those that are inactive for some analyzer setups SOLID softkey See LINE TYPE softkeys 9 124 Key Reference SOURCE AMPLITUDE softkey SOURCE AMPLITUDE softkey Key Path Source Press this key when you want to change the output amplitude of the source You are prompted to enter a new output level either in dBm or Vrms The range of values for SOURCE AMPLITUDE is 59 9 dBm to 10 dBm when the output impedance is 500 The smallest possible increment between values
90. andwidth 17 kHz Otherwise you may have difficulty finding your test signal particularly if you haven t set the center frequency to exactly the same frequency as your test signal Because the analyzer functions as a fixed tuned receiver in manual sweep the analyzer s tuning is too sharp with a narrow resolution bandwidth to detect a test signal that isn t exactly at the specified center frequency Narrow resolution bandwidth settings provide selectivity to exclude closely spaced signals If you carefully set the center frequency you can use a narrow resolution bandwidth to exclude signals that are close to the frequency of your test signal Narrow resolution bandwidths settings provide better noise reduction Use a narrow resolution bandwidth to lower the noise floor this maximizes the dynamic range Select appropriate trace type If you want to measure amplitude in dBm use the logarithmic magnitude trace type If you want to measure amplitude in volts use the linear magnitude trace type You can use the frequency counter and the noise level function Both the frequency counter and the noise level marker are available in manual sweep although using either will slow your measurement The manual frequency you specify must be within the current span If you specify a manual frequency that is outside the current span the analyzer snaps the manual frequency to the nearest available frequency For example if you specify a
91. asurement Point lt o oo oo ooo et ee eee roo os 8 4 Stepping the Manual Frequency dica AAA A AR EEE SRE at 8 4 SAMPLE TASK Stepping the Manual Frequency over a Wide Span ned RATES 8 5 Chapter 9 Key Reference How touse thischapter ost sonene Fo EN Se pe RS Re a a Ry A eee 9 1 Kev Reference ecu RR AE AA A AAN 9 2 Alpha entry meni 1 A Sed AS AAA AA AA AAA OS 9 3 Alpha entry mode 4 45 6 4 6 ss oss AR y aa FG 9 3 Chapter 10 Menu Map Measurement Group AAA IA ARA RA ee ATA Bee re 10 1 Display Group sea Sis hos AR eh eh oe BE Oe ES AGE A Ree 10 3 Marker Group ceco oca e e Fae A A ad See ee Gee A oe 10 5 System Group A E a ee ee ee aaa ec ee be lea 10 6 Before You Begin How to Use this Book Are you using the correct book This operating manual provides a detailed overview of the analyzer s controls and features As such it s the correct book to use if you re already comfortable with the HP 3588A Spectrum Analyzer and what you really need is more in depth information about specific instrument controls and features If you haven t used the analyzer before or haven t used it very much make sure you ve already read the HP 35884 Getting Started Guide This contains sample measurement tasks and essential background information necessary for you to get comfortable quickly with the HP 3588A Spectrum Analyzer Averaging Getting Started Operating Manual Copy operations Getting Started Operating Manual
92. ault Trace Type Log Magnitude 2 28 Front Panel Overview The Preset Key MEASUREMENT group pra Hold option Off Number Averages 10 Res BW 17 kHz Vid Fitr Off BW Couple On Zoom Type Hi Accrcy Zoom Sweep Auto Manual Freq 75 05 MHz Sweep Time 260 8 ms Sample Time 4 us Oversweep On m 75 05 MHz Span 149 9 MHz Start 100 0 kHz Stop 150 0 MHz Step Size Auto User Step Size 1 kHz Signi Trk OFF eos On Input Impedance 50 Q 1 Meg Ref Imped 50 Q Solido State Off Source Amplitude 10 0 dBm Amplitude Step 0 1 dBm Output Z 50 Q Z Coupling On i Trigger Ty Type Free Run Arm Auto 2 29 Front Panel Overview The Preset Key SYSTEM group A Tousen Echo Off _ Dis Format Option o a Interleave Factor 1 Catalog Off PloV Print hardke race Pen 2 Trace B Pen 3 Marker A Pen 5 Marker B Pen 6 Alpha Pen 4 Graticule Pen 1 Trace A Line Type Solid User Defined line A 4096 Trace B Line Type Solid User Defined line B 4096 Piot Speed Fast 50 cm s User Defined speed 50 cm s Page Ejct On Spel Fein Auto Cal On Beeper On Srce 10dB Out Srce 20dB A Out Srce 20dB B Out Srce DAC Atten 0 dB These parameters are not affected by Preset but are returned to the following values at power up Function registers cleared Constant registers cleared Data registers cleared Limit registers cleared Memory Size 8192
93. ay the current date at the top of the screen The date is read from the analyzer s battery backed clock After pressing this softkey you can enter a new date with the number keys The date must be entered in the format noted on the softkey label the first two digits set the month the second two digits set the day the last two set the year Here s an example August 3 1990 Press DATE MMDDYY 0 8 0 3 9 0 ENTER DEBUG softkey Key Path User Define DEBUG displays a menu The softkeys in the menu help you locate and correct errors in your HP Instrument BASIC program The Debug menu keeps RUN and CONTINUE from the main HP Instrument BASIC menu and adds the following softkeys m SINGLE STEP J lets you execute your program one line at a time LAST ERROR lets you examine the last error number and message generated by your program EXAMINE VARIABLE lets you examine the current value of any program variable RESET lets you reset HP Instrument BASIC to its default state 9 19 Key Reference Decimal point hardkey Decimal point hardkey This hardkey has two functions w When you are changing a numeric parameter Press this hardkey to enter a decimal point u When you are changing a text string Press this hardkey to insert a period or decimal point to the left of the cursor DEFAULT DISK softkey Key Path Save Recall or Disk Util This softkey displa
94. be at least one display point to the right of the current marker location If the peak search algorithm doesn t find a peak the marker doesn t move Hint Decrease the value of VERTICAL DIV to increase the number of peaks found Use any of the marker search keys including NXT RIGHT PEAK J with offset markers to quickly measure frequency and amplitude differences between two signals OFF softkey Avg Pk Hid Key Path Avg Pk Hid Press this softkey to disable the video average and peak hold functions When OFF is selected each trace update represents the results of a single measurement 9 80 Key Reference OFFSET ON OFF softkey OFFSET ON OFF softkey Key Path Marker Press OFFSET ON OFF to enable and disable the offset marker for the active trace The analyzer has one offset marker for each trace The offset marker is the square shaped marker that remains at a fixed location even when a trace is updated To reposition the offset marker you must move the main marker to a new location and then press ZERO OFFSET When the offset marker is on the analyzer subtracts the offset marker position from the main marker position to establish the x and y values of the marker readout The readout is preceded by the delta symbol to show that this difference is being displayed Use the offset markers with any of the marker search keys to quickly measure frequency and amplitude differences between two sign
95. bout HP Instrument BASIC a subset of the HP BASIC programming language see Using HP Instrument BASIC with the HP 35884 Spectrum Analyzer Additionally you will find applications information in numerous Hewlett Packard application notes These are available from your local HP Sales and Service Office In particular you might want to request some of the following application notes u AN 150 series several application notes some recently updated that cover many topics dealing with spectrum analysis m AN 246 1 Optimizing the Dynamic Range of the HP 3585A Spectrum Analyzer u AN 378 1 Harmonic Distortion Measurements Before You Begin About the Analyzer About the Analyzer The Hewlett Packard 3588A is a swept tuned spectrum analyzer with a frequency range of 10 Hz to 150 MHz As such the instrument is a general purpose design tool for measurement and evaluation of many electronic devices In addition a built in source tracking generator lets you perform scalar network analysis for filters amplifiers and other devices You can also operate the analyzer remotely via the HP IB to make automated measurements a feature that s particularly useful for repetitive tasks such as those encountered in production line testing The HP 3588A offers two measurement types Swept Spectrum and Narrow Band Zoom Both provide excellent resolution and operate at speeds far greater than conventional analyzers Swept spectrum measurements provid
96. bsequent presses the analyzer executes the displayed line and then displays the next line to be executed Program lines are displayed at the top of the screen If your program is paused single stepping begins with the line following the last executed line If your program has been stopped or reset single stepping begins with the first line Note If you change edit a paused program it is reset automatically y You can use EXAMINE VARIABLE to see what has happened after each line is executed Softkeys in bracketed groups Some softkeys are grouped together with a bracket like this SWEPT SPECTRUM NARROW BAND ZOON Lerma The keys in such a group select options that are mutually exclusive at any given time only one of the options can be active The analyzer indicates which option is active by drawing a box around that option s softkey label In the example above swept spectrum is active 9 123 Key Reference Softkeys that toggle Softkeys that toggle Some softkeys control analyzer functions that have only two states for example on and off Each time you press one of these keys the associated function toggles switches from one state to the other Here is an example of a toggling softkey SWEEP AUTO MAN The analyzer indicates which state is active by highlighting the corresponding text on the softkey label In the example above manual sweep is active If you were to press this ex
97. cate inactive links in help text FORMAT DISK softkey Key Path Disk Util The format disk softkey displays a menu The softkeys in the menu allow you to define some formatting parameters and to format a disk using those definitions FORMAT OPTION Lets you define the storage capacity of the disk m INTRLEAVE FACTOR Lets you define the spacing between sectors only used for flexible disks m PERFORM FORMAT Starts formatting the disk after prompting you for the disk specifier Note The analyzer s internal disk drive can read and write single sided disks but it can xd only format double sided disks 50 OHMS softkey See Input Impedance softkey group 50 OHMS OUTPUT Z softkey See Output Impedance softkey group 9 38 Key Reference Format hardkey Format hardkey The Format hardkey displays a menu that is used to configure the analyzer s screen The softkeys in this menu allow you to do the following things s Select one of three formats for displaying traces u Display a summary of current analyzer settings Reduce the amount of information on the screen FORMAT OPTION softkey Key Path Disk Util gt FORMAT DISK Press FORMAT OPTION to define the storage capacity of the disk you will format An entry box is displayed so you can enter a new value The format options are actually encoded values that give you the following capacities RAM NVRAM Inte
98. cy span to better resolve some portion of the spectrum On the HP 3588A display each span is divided into 401 evenly spaced points As you narrow the span the frequency increment between points decreases thus increasing the display resolution Zoom Type softkey group Key Path Res BW The two keys in this softkey group let you choose between greater amplitude accuracy and greater frequency resolution for narrow band zoom measurements HI ACCRCY ZOOM provides greater amplitude accuracy HIRES ZOOM provides greater frequency resolution Hint When you are trying to resolve closely spaced signals that differ greatly in amplitude HI ACCRCY ZOOM sometimes provides better frequency resolution 9 147 4 amp Menu Map Measurement Group Meas Type hardkey SWEPT SPECTRUM NARROW BAND ZOOM LOW DIST ON OFF PEAK DET ON OFF Freq hardkey CENTER SPAN FULL SPAN ZERO SPAN START STOP STEP SIZE AUTO USER USER STEP SIZE SIGNL TRK ON OFF Res BW hardkey RES BW VID FLTR ON OFF VIDEO BW BW COUPLE ON OFF BW COUPLE PRESET HI ACCRCY ZOOM HI RES ZOOM Meas Restart hardkey Range Input hardkey RANGE AUTORANGE ON OFF SINGLE AUTORANGE 50 OHMS 75 OHMS 1 MEGOHM 1 MEG REF IMPEDANCE CLEAR INP TRIP Menu Map Measurement Group Sweep hardkey SWEEP AUTO MAN MANUAL FREQ
99. d very long sweep times for small frequency spans due to the narrow resolution bandwidths required to provide adequate frequency resolution The narrower the resolution bandwidth the more time it takes for the resolution bandwidth filters to settle In fact a swept tuned analyzer s sweep time is proportional to the square of the resolution bandwidth As you choose increasingly narrower resolution bandwidths for example when trying to resolve close in sidebands the time it takes to make a measurement increases exponentially This characteristic is common to all conventional swept tuned spectrum analyzers However the HP 3588A Spectrum Analyzer can make narrow band measurements very quickly with narrow band zoom This lets you make measurements for small spans 40 kHz and less much faster than you can with a swept spectrum measurement For narrow band zoom measurements the analyzer uses an FFT Fast Fourier Transform an implementation of the Discrete Fourier Transform to convert the input data from the time domain to the frequency domain The result is measurement capability more than thirty times faster than conventional swept only analyzers Narrow Band Zoom is ideal for narrowband analysis of close in sidebands And it s easy to do First set the analyzer s center frequency to the carrier frequency you want to examine Then press Meas Type and then NARROW BAND ZOOM 5 1 Narrow Band Zoom Measurements Setting the Center F
100. d when you press the PRINT PROGRAM softkey in the User Define menu A displayed Help screen is printed when you press 8 9 94 Key Reference PLOTTER ADDRESS softkey PLOTTER ADDRESS softkey Key Path Local HP 18 gt PERIPHERL ADDRESSES Press this softkey to tell the analyzer what address is currently assigned to your HP IB plotter See your plotter s documentation if you don t know how to determine its HP IB address A prompt is displayed so you can enter the address Note The plotter address is saved in non volatile memory so it is retained when you turn a the analyzer off and on When you plot screen contents the analyzer looks for a plotter at the address specified with this softkey If there isn t a plotter at the specified address the plot is aborted Plus softkey See Operator Menu 9 95 Key Reference Preset hardkey Preset hardkey You can return the analyzer to a known state by pressing Preset This known state provides a convenient starting point when you are setting up a new measurement The analyzer s preset state is described on the following pages Individual parameters are organized first by hardkey group then by hardkey Note The listed parameters are also returned to their preset values at power up unless i you have created an AUTO _ST file MARKER group Marker Hardke Marker Fetn X Entry 75 05 MHz Peak Trk Off Offset Off Freq Cntr Of
101. deo Bandwidth Video Filtering and Video Bandwidth Video filtering is another feature common to many swept tuned spectrum analyzers A video filter is a variable bandwidth low pass filter placed between the analyzer s detector and the display The amount of video filtering is determined by the video bandwidth often called VBW Video filtering is normally off To turn on video filtering press Res BW and toggle to VID FLTR ON OFF Then press VIDEO BW and use the numeric entry keys or the knob to specify the video bandwidth The range of available video bandwidth varies depending on the current resolution bandwidth setting It s important to understand the difference between resolution bandwidth and video bandwidth Narrowing resolution bandwidth reduces noise in a measurement In contrast video filtering does not reduce noise instead it simply reduces the variation in the noise level and smooths the noise floor Video filtering like resolution bandwidth also affects the analyzer s sweep time Using a narrow video bandwidth slows down a measurement considerably To learn more about video bandwidth and what it does see the sidebar called Understanding Resolution Bandwidth and Video Bandwidth 4 4 Swept Spectrum Measurements Bandwidth Coupling Bandwidth Coupling Overview The automatic adjustment of resolution bandwidth sweep time and video bandwidth for different frequency spans is called
102. des a high impedance input useful for general purpose measurements up to 40 MHz where optimal amplitude accuracy and dynamic range are not required Because this input is shunted by approximately 30 pF you can attach a compatible high impedance oscilloscope probe Although the 1 MQ input restricts the analyzer to a single input range maximum input of 223 mVrms there are nonetheless many measurement situations where the 1 MQ input is extremely useful For example if you need to do the following perform in circuit probing of low frequency devices m bridge a terminated transmission line without disturbance terminate the 1 MQ input to match the output impedance of a specific signal source Note The 1 MQ input is designed to measure frequencies up to 40 MHz Although the pl 1 MQ input is functional over the entire frequency range of the analyzer measurement performance above 40 MHz is not specified Front Panel Overview Active Probe Power Connector Active Probe Power Connector Some in circuit measurements require even less capacitance than the 30 pF provided by the analyzer s 1 MQ input For these situations you can use an active probe in conjunction with the 509 input Power for the active probe is supplied by this small connector located between the input and source connectors There is currently one active probe available that is compatible with the HP 3588A Spectrum Analyzer the HP 41800A Active Probe You may al
103. device with great precision For general device characterization it s not really necessary To make a normalized measurement remove your test device and replace it with a barrel connector This removes your test device from the measurement path Now make a network measurement without the test device this reveals the amplitude errors introduced by the test fixture and the analyzer s source Don t forget to record the results by pressing Trace Data and SAVE NORM REFERENCE Afterwards replace your test device and make another network measurement Then press Trace Data and NORMALIZED SPECTRUM This lets you view the response of the test device with the amplitude errors removed normalized To learn more about normalizing a scalar network measurement and to step through a sample normalization sequence see the HP 35884 Getting Started Guide 7 2 Measurement Enhancements Trace Math Trace Math Overview Trace math lets you perform a variety of operations on current or stored traces You can use trace math to modify the results of a spectrum measurement for example to compensate for a fixed gain or loss in a measurement system You can also use trace math to normalize measurement results for scalar network analysis However this really isn t necessary since the analyzer performs the normalization process automatically when you use the SAVE NORM REFERENCE and NORMALIZED SPECTRUM softkeys see
104. dkey The analyzer has two independent display buffers for trace data trace A and trace B The Active Trace hardkey allows you to toggle between these two buffers making one active and the other inactive so they can be modified separately When you use a two trace format annotation fonts and line types indicate which trace is active A bold font and solid line are used for the active trace A ghosted font and dotted line are used for the inactive trace When you use the single trace screen format only the active trace is displayed With a few exceptions the softkeys grouped under the following hardkeys only affect the active trace m Trace Type J m Trace Data Scale Marker w Marker Fetn ADDRESSBL ONLY softkey See Controller Capability softkey group 9 2 Key Reference Alpha entry menu Alpha entry menu The alpha entry menu and its submenus provide access to special characters and string editing functions when the analyzer is in the alpha entry mode ENTER accepts the current string and exits the alpha entry mode CANCEL RETURN abandons the string and exits alpha entry CLEAR ENTRY deletes the string but does not exit alpha entry DELETE CHARACTER deletes the character under the cursor INSERT SPACE inserts a space to the left of the cursor The two Morechars softkeys bring up submenus for inserting special characters to the left of the cursor UPPERCASE lowerca
105. e SECURE softkey SECURE softkey Key Path User Define gt UTILITIES SECURE displays a menu You use the softkeys in the menu to do two things a Specify a range of lines in your program that you want to secure w Secure protect against viewing the specified range of lines Caution Secured program lines can not be unsecured Be sure to keep an unsecured version y of the program for your own records SERIAL NUMBER softkey Key Path Spel Fetn Press this softkey to display your analyzer s serial number SETUP STATE softkey See Display Format softkey group trace 75 OHMS softkey See Input Impedance softkey group 75 OHMS OUTPUT Z softkey See Output Impedance softkey group 9 120 Key Reference SIGNL TRK ON OFF softkey SIGNL TRK ON OFF softkey Key Path Freq The analyzer can change its center frequency automatically to track a drifting signal The SIGNL TRK ON OFF softkey allows you to enable and disable this feature When signal tracking is enabled the analyzer adjusts the value of CENTER to keep the largest signal centered in the current frequency span The effect of signal tracking is similar to the effect you would get by continuously pressing the following key sequence MKR gt PEAK MKR gt CTR FREQ J The difference of course is that the analyzer can do this quickly enough to ensure that it occurs once for each measurement
106. e HP Instrument BASIC option is not installed the analyzer displays an error e message when you press this key User Define has a special purpose in each of the following situations HP Instrument BASIC s keystroke recording feature is enabled In this situation you can press User Define to end the current recording session An HP Instrument BASIC program is running In this situation you can press User Define to pause the program You can also stop a program in other ways USER SRQ softkeys Key Path Local HP 1B Press USER SRQ J to gain access the softkeys USER SRQ 0 through USER SRQ 9 Each of the numbered SRQ softkeys allows you to interrupt an external HP IB controller from the analyzer s front panel The number on each SRQ softkey corresponds to the number of a bit in the analyzer s User Status event register When you press one of these keys the corresponding bit is briefly pulsed high logic 1 Note These keys are only useful if the analyzer s User Status register set is programmed to respond to them See the HP 35884 HP IB Programming Reference for more information 9 141 Key Reference USER STEP SIZE softkey USER STEP SIZE softkey Key Path Freq Use USER STEP SIZE to define the effect of the knob and arrow keys on the value of the following frequency parameters m CENTER m START STOP m MANUAL FREQ J When you change the value of these pa
107. e entered under the PRINTER ADDRESS softkey matches the setting on your printer o PRINT PROGRAM softkey Key Path User Define Press PRINT PROGRAM to print list your HP Instrument BASIC program The following things must be true in order for your program to print The analyzer must be the system controller The printer must be turned on attached to the analyzer s HP IB connector and set to the address specified under the PRINTER ADDRESS softkey 9 99 Key Reference PRINTER ADDRESS softkey PRINTER ADDRESS softkey Key Path Local HP IB gt PERIPHERL ADDRESSES Press this softkey to tell the analyzer what address is currently assigned to your HP IB printer See your printer s documentation if you don t know how to determine its HP IB address A prompt is displayed so you can enter the address Note The printer address is saved in non volatile memory so it is retained when you turn s the analyzer off and on When you print screen contents the analyzer looks for a printer at the address specified with this softkey If there isn t a printer at the specified address the print is aborted 9 100 Key Reference RANGE softkey RANGE softkey Key Path Range Input Press RANGE to manually change the sensitivity of the analyzer s input circuitry The range setting determines the maximum ac signal level that can be applied to the input connector without overdriving the in
108. e independent samples for each measurement Use the longer sample times when you average manual sweeps 9 111 Key Reference SAVE AUTO STATE softkey SAVE AUTO STATE softkey Key Path Save Recall SAVE AUTO STATE saves the current instrument state to a special file on the non volatile RAM disk The file is called AUTO_ST When you turn the analyzer on it searches for AUTO_ST and uses the contents to define its power up state The analyzer searches two disks for the file They are searched in the following order 1 Non Volatile RAM disk 2 Internal disk The analyzer uses the power up state described under Preset if it does not find an AUTO_ST file Hint Any state file can be renamed AUTO_ST and used to define the analyzer s power up state SAVE LOWER LIM softkey Key Path Save Recall gt SAVE MORE Use SAVE LOWER LIM to save the lower limit line of the active trace to one of the disks The limit line is saved to the default disk unless you include a disk specifier in the filename prompt Caution The volatile RAM disk is cleared each time you turn the analyzer off Copy Y important limit files to another disk before power down or they will be lost When you save a lower limit you are prompted for a filename If the catalog is off the prompt contains a default filename L_LIM If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in
109. e reference output reference output 3 6 resolution bandwidth 4 3 4 6 9 109 resolution bandwidth coupling See bandwidth coupling RNG See input S save recall operations 9 118 scalar network measurements 7 1 special considerations 7 2 scalar network measurments normalization of 7 2 scan time See sweep time setup state 2 27 after power up 2 28 after preset 2 28 printing 2 27 signal track 7 6 9 121 See also peak track softkeys 1 2 2 11 9 123 toggle 1 2 softkeys toggle 2 11 source 2 7 9 125 amplitude 9 125 amplitude step size 9 4 output impedance 9 83 protection circuitry 2 8 span See frequency span special function keys 9 128 wee index Continued spectrum analyzers and radio receivers 4 6 status message area See display step size 2 20 and center frequency 7 7 and center frequency sample task 7 8 and manual frequency 8 4 and manual frequency sample task 8 5 modifying 7 7 user 7 7 using the frequency counter to set 7 7 sweep time 4 10 9 134 sweep manual See manual sweep swept spectrum measurements 4 1 9 135 See also narrow band zoom measurements system keys 2 26 T time setting analyzer s clock 9 136 trace math 7 3 and logarithmic values 7 4 constants 9 22 data registers 9 19 9 29 functions 9 21 9 45 operand menu 9 82 operator menu 9 83 special considerations 7 3 trace title See display tracking generator See source TRIG OUT See trigger output trigger 9 139 arming 9 4 freerun 9
110. e single frequency you want to analyze Note An additional frequency softkey MANUAL FREQ is located under the Sweep mg hardkey There are two pairs of softkeys in this menu that allow you to define a frequency band one of the pairs is CENTER and SPAN the other is START and STOP In each of these pairs the current value of one softkey is held constant when you change the value of the other Note The offset between START and STOP is held constant during narrow band zoom y measurements X axis scaling is normally linked to the frequency parameters So if you set START to 10 MHz and STOP to 30 MHz then a trace s x axis will start at 10 MHz and stop at 30 MHz X axis scaling is linked to SWEEP TIME if ZERO SPAN is selected Two softkeys in the Freq menu define special frequency bands with one key press m FULL SPAN defines a 150 MHz span centered at 75 MHz a ZERO SPAN defines a 0 Hz span centered at the current center frequency You can alter the analyzer s frequency parameters in steps using either the knob or the arrow hardkeys Two softkeys in the Freq menu STEP SIZE USER AUTO and USER STEP SIZE allow you to define the step The last softkey in the Freq menu SIGNL TRK ON OFF gives you access to an analyzer function that can track a drifting signal Note Some softkeys in the Freq menu behave differently for each of the two y mea
111. e specified by SWEEP TIME When the peak detector is on increasing the sweep time can cause apparent increases in the noise floor level assuming you hold the span and resolution bandwidth constant With longer sweep times the analyzer spends more time detecting peaks for a given display point This increases the chance that a larger peak will be detected if the frequencies represented by the point contain only noise energy You can change SWEEP TIME in the usual ways but with the following conditions The analyzer changes any value you enter with the number keys to the closest available value m The current sweep time is changed by a factor of 2 when you turn the knob slowly or press an arrow key one time When you change the sweep time this creates a new relationship between the sweep rate and the resolution bandwidth If bandwidth coupling is turned on the analyzer maintains this new relationship by changing the sweep time when the resolution bandwidth changes When you press BW COUPLE PRESET the analyzer chooses the shortest available sweep time that can provide calibrated measurement results If you specify a shorter sweep time the UNCAL indicator is displayed on the bottom line of the screen Note The analyzer selected sweep time is usually shorter when oversweeping is turned on Y 9 134 Key Reference SWEPT SPECTRUM softkey SWEPT SPECTRUM softkey Key Path Meas Type Press SWEPT SPE
112. e the performance and features found in traditional Hewlett Packard swept tuned analyzers but incorporate very sharp digital IF filters to provide improved frequency resolution down to 1 14 Hz For narrow band zoom measurements the analyzer uses an implementation of the Fast Fourier Transform to provide faster measurements with even greater resolving power Faster measurements are possible with swept spectrum measurements since the analyzer uses digital IF filters With selectivity nearly twice that of analog filters digital filters offer faster measurements while still resolving low level carrier sidebands Additionally the inherent predictability of digital filters permits the analyzer to sweep even faster using a built in correction algorithm This provides increased measurement speed up to four times faster than conventional swept tuned analyzers for comparable measurements with no additional amplitude error or resolution loss Narrow Band Zoom provides the fastest spectrum measurements more than thirty times faster than swept tuned analyzers for comparable measurements with resolution performance unequalled by traditional technologies Narrow Band Zoom can be used for spans of 40 kHz and less and is ideal for narrowband analysis of close in sidebands 1 4 Before You Begin About the Analyzer Front Panel Overview With few exceptions individual hardkeys and their associated softkeys are not described in this section Fo
113. ected though large components just below and just above the displayed frequency range may cause an OVLD condition Front Panel Overview Input Input Trip If you exceed the maximum absolute input level the analyzer s protective circuit breaker may trip 50 75 input only After removing the input signal press Input and then CLEAR INP TRIP Caution Although the analyzer s input has protection circuitry signals greater than the 7 following may damage the analyzer 50 75Q input 1 MQ input RF signals greater than 26 dBm 5002 or 28 dBm 75Q de offsets greater than 4 V peak combined ac dc signals greater than 25 volts peak peak combined ac dc signals greater than 4 Vpeak The 50 Input This is the most commonly used input impedance When selected the input connector is terminated with a 50Q resistance Since the default impedance is 50 this will be the input configuration selected after you turn on the analyzer or press Preset The 752 Input When you select the 75Q input impedance the analyzer makes the necessary adjustments to calculate dBm values for a 75Q input impedance However the input remains terminated with a 50Q resistance and you must therefore connect a 25Q adapter a series feedthrough barrel between the input signal and the analyzer s input This provides the necessary 75 to 50Q conversion 2 4 Front Panel Overview Input The 1 Me Input The 1 MQ input provi
114. ectrum measurement SYSTEM CONTROLLR softkey See Controller Capability softkey group 9 135 Key Reference TEST EVAL ON OFF softkey TEST EVAL ON OFF softkey Key Path Marker Fetn gt LIMIT TEST Press TEST EVAL ON OFF to enable and disable testing of the active trace against its current limits Note If you want limit lines to be displayed during the test toggle LINES ON OFF to ON Y A trace fails a limit test if any of its points fall outside the current limits Results of the test are displayed in the lower left corner of the trace box TIME HHMM softkey Key Path Spel Fetn Press TIME HHMM to display the current time at the top of the screen The time is read from the analyzer s battery backed clock After pressing this softkey you can enter a new time with the number keys The time must be entered in a 24 hour format the first two digits set the hour the second two digits set the minute Here are a couple of examples a 8 05 am Press TIME HHMM 0 8 0 5 ENTER m 3 42 pm Press TIME HHMM 1 5 4 2 ENTER TRACE A LINE TYPE softkey Key Path Piot Print gt DEFINE PLOT Press TRACE A LINE TYPE for access to the line type softkeys The line type you specify with these softkeys will be used to plot trace A Note Check your plotter s documentation to be sure that it supports the requested 1 line type 9 136 Key
115. een automatic and manual sweeping during swept spectrum measurements Note SWEEP AUTO MAN is not used for narrow band zoom measurements y When you toggle this softkey to AUTO the analyzer sweeps automatically through the specified band of frequencies You can control the speed of automatic sweeps with the SWEEP TIME softkey When you toggle this softkey to MAN the analyzer measures at discrete points within the specified band of frequencies You define these points by changing the value of MANUAL FREQ You can manually sweep through these points by using the knob to continuously change the value of MANUAL FREQ Note The value of MANUAL FREQ is maintained as you toggle between automatic and y manual sweeping When you toggle to manual sweeping the trace updates stop for all points except the manual measurement point The manual measurement point is the display point that contains the manual frequency Most of the trace appears to freeze but the manual measurement point appears to lt 33 wiggle While you are changing the manual frequency the main marker tracks the manual measurement point but it s also possible to move the marker independently Hint Ifthe MANUAL FREQ entry box is displayed you can only use the knob to change the manual frequency Press Sweep Marker or some other hardkey to remove the entry box from the screen and free the knob for marker move
116. eep peak track updates the marker via marker readout every time the display is updated with the manual sweep result Note Peak track will turn the marker ON if it is not already ON 4 6 5 Marker Functions Frequency Counter Frequency Counter Overview When you turn on the frequency counter the marker readout no longer reflects the nominal frequency value for the display point Rather the analyzer calculates a more accurate frequency value every time it sweeps past the marker position If the offset marker is on the counter shows the frequency offset from the offset marker position To turn on the frequency counter press Marker Fetn and toggle to FREQ CNTR ON OFF J The frequency counter is especially useful for accurately entering a frequency value during numeric entry If you ve turned on the counter the analyzer uses the frequency counter not the marker position when you press Marker Value As we mentioned earlier setting the center frequency accurately is particularly important before making narrow band zoom measurements Counting Behavior When the counter is on for swept measurements the analyzer sweeps to the marker position counts and then completes the sweep If you ve selected manual sweep the analyzer simply counts the currently tuned manual frequency During narrow band zoom measurements the analyzer completes one measurement and then counts When a count has been completed the
117. el supplied with the analyzer for accurate results Insert the adapter between your test signal and the input connector When you select 1 MEGOHM J the input connector is terminated with a 1 megohm resistance The dBm calculations use the impedance value you specify under the 1 MEG REF IMPEDANCE softkey Three special restrictions apply when you select the 1 megohm input impedance Only the 0 dBm range referenced to 50 ohms is available Continuous autoranging is disabled as a result a The analyzer s performance is only specified between 10 Hz and 40 MHz a Source impedance does not match input impedance even if COUPLE TO INPUT Z is selected INPUT SPECTRUM softkey Key Path Trace Data Press INPUT SPECTRUM to display the contents of the input spectrum buffer in the active trace The buffer contains calibrated input data from the current measurement The analyzer sends new input data to the input spectrum buffer each time a measurement is completed Ifthe video average or peak hold function is selected the data is combined with the current contents of the buffer The buffer is then updated with the combined data If neither of these functions are selected the buffer is updated immediately with the new data 9 53 Key Reference Insert lt chars gt softkeys Insert lt chars gt softkeys Key Path User Define gt EDIT gt TYPING UTILITIES Each INSERT lt chars gt softkey g
118. enter frequency based on the marker value press CENTER then Marker Value However this method has the following disadvantages a The main marker does not move to the new center frequency The analyzer uses the offset value if the offset marker is on MKR gt PEAK softkey Key Path Marker Press the MKR gt PEAK softkey to move the marker to the highest peak on the active trace Once moved the marker remains at the new x axis location until you do one of the following things m Turn the knob with no entry box displayed a Press another marker search key a Enter a new x axis location using MARKER X ENTRY Note The analyzer can automatically move the marker to the highest peak each time the g active trace is updated To enable this feature turn on peak tracking 9 71 Key Reference MKR gt REF LEVEL softkey MKR gt REF LEVEL softkey Key Path Marker When you press MKR gt REF LEVEL the analyzer s reference level is reset to the current y axis value of the main marker the diamond shaped marker Here s how MKR gt REF LEVEL works in some special cases The analyzer uses the y axis position of the main marker even if the noise level measurement is enabled The analyzer uses the main marker value even if the offset marker is on There is another way to change the reference level based on the marker value press REFERENCE LEVEL then Marker Value
119. er to more accurately determine signal frequency at the main marker position Determine the noise level at the main marker position Define limits and enable limit testing 9 65 Key Reference Marker hardkey Marker hardkey The Marker hardkey displays a menu You use the softkeys in this menu to control basic marker functions in the active trace The marker readout is displayed directly above the trace box Note Additional marker functions are available under the Marker Fetn hardkey y The analyzer s basic marker functions allow you to do the following things Enable and disable all markers or just the offset markers w Position the main marker and the offset marker along a trace includes peak search w Change frequency parameters center and span based on the markers x axis positions Change the reference level based on the main marker s y axis position Hint When a numeric entry box is displayed turning the knob changes the value in the box it does not move the marker To ensure that the knob will move the marker press Marker first MARKER ON OFF softkey Key Path Marker Press MARKER ON OFF to enable the main marker or to disable all markers at once When you toggle this softkey to OFF both markers main and offset in both traces are turned off The marker readout and the following marker functions are also turned off m Peak tracking m Frequency counting m Noise l
120. ert seater Tester Tetra rr errr Terer terior tt ritiry Canter 282 728 7 Hz Front Panel Overview Display Area X axis Notation Range B dem 22 Dec 198 13 34 UBH OFF Sup Time 524 8 mSec kr 73 526 989 Hz 1 98 dBm Res BW 17 BBA H2 A EOIN i dBm LogMag i 2 0R div X axis Notation The x axis notation indicates the frequency range the analyzer is using to make the current measurement For stored traces the x axis notation indicates the frequency range used to acquire the stored data The x axis notations indicates the frequency range one of two ways m by showing the center frequency and span for example a center frequency of 55 MHz and a span of 90 MHz by showing the start and stop frequencies for example a start frequency of 10 MHz and a stop frequency of 100 MHz The particular notation used reflects the most recent way you entered frequency range parameters For example if you used the SPAN or CENTER softkeys to specify a frequency range the analyzer will express the frequency range using span and center frequencies If you used the START and STOP softkeys the analyzer will use start and stop frequencies 2 17 Front Pane Overview Display Area Status Message Area Range B dBm 29 Dec 1989 13 34 Res Bu 17 802 Hz VER OFF Sun Time 524 8 mSec 3 mxr 73 526 B8 M2 1 43 Am Dn A ere PA Cp RANA RNA GITANA teratenrer seer nano rp raras Status Message Area
121. erview Numeric Entry Keys The Arrow Keys Like the knob you can use the arrow keys to step through larger or smaller numeric entries Press lt gt to step through increasingly larger numeric entries for example to raise the current center frequency Press to step through increasingly smaller numeric entries for example to lower the current cent r frequency You can use the arrow keys to modify a numeric entry at any time unlike the knob which you can use for numeric entry only after pressing a softkey to activate the numeric entry mode And like the knob the analyzer uses the same default step size to control the sensitivity of the arrow keys that is the interval between each numeric entry as you press an arrow key As we mentioned earlier you can select your own step size Press Freq toggle to STEP SIZE AUTO USER and press USER STEP SIZE Then use the numeric keypad to enter your own step size To learn more about setting the step size to your best advantage see chapter 7 Measurement Enhancements 2 22 Front Panel Overview Alpha Entry Keys Alpha Entry Keys It is occasionally necessary to specify alpha characters for example when entering a trace title or when saving or recalling a specific file During these times the analyzer automatically shifts certain front panel keys to an alpha entry keys note the alpha characters engraved on the front panel below these ha
122. ether to define a frequency band you want to analyze START defines the band s lower limit STOP defines its upper limit Here s how START and STOP work together for each of the two measurement types a For swept spectrum measurements the value of one is held constant when you change the value of the other a For narrow band zoom measurements the offset between START and STOP is held constant when you change the value of either Hint Press START or STOP to change x axis annotation from center span to start stop You can also use CENTER and SPAN to define a frequency band In fact these two keys are usually more convenient when you are zooming on a single peak in the spectrum START and STOP both accept the same range of values 0 Hz to 150 MHz although the analyzer s performance is not specified below 10 Hz You can change either key s value in the usual ways but with the following enhancements You can control the sensitivity of the knob and arrow keys with STEP SIZE AUTO USER and USER STEP SIZE e You can set either key to the marker s current x axis value with the Marker Value hardkey The HP 3588A only sweeps up from a lower frequency to a higher one so it enforces the following relationship START STOP If you enter a new start or stop frequency that violates this relationship both keys are set to the new frequency This has the same effect a
123. evel measuring When you toggle this softkey to ON the main marker and the marker readout are turned on automatically However you must turn on the offset markers and the listed marker functions with the appropriate softkeys 9 66 Key Reference Marker Value hardkey Marker Value hardkey Press Marker Value to use the current value of the marker readout for the active numeric entry softkey Marker Value uses the x axis readout if the numeric entry softkey requires a frequency value It uses the y axis readout if the softkey requires an amplitude value Marker Value does not use the displayed y axis readout if the noise marker is enabled Instead it uses the value that would be displayed if the noise marker was disabled Marker Value can not be used at all for frequency parameters when zero span is selected This is because the readout s x axis unit is seconds rather than hertz in this case MARKER X ENTRY softkey Key Path Marker Press MARKER X ENTRY when you want to place the main marker on a particular display point of the active trace The analyzer has one main marker for each trace The main marker is the diamond shaped marker that follows trace contours You move the main marker to a new point on a trace by changing its x axis value The analyzer then displays the x and y values of that point in the marker readout You don t need to select MARKER X ENTRY to move the main marker with the
124. ey The softkeys grouped together under Math are used to define trace math functions and constants The trace resulting from a particular function or constant can be displayed by pressing the corresponding Fx or Kx softkey under the Trace Data hardkey Note The analyzer does some limited tracking of units in trace math operations 4 All math operations are performed on linear rather than logarithmic data Since you cannot create functions that add or subtract logarithmic values you must create equivalent functions that multiply or divide linear values This is why a normalized spectrum is defined as SPEC D8 Suppose you want to add 3 dB to your measurement results Just convert the logarithmic offset to its linear equivalent and multiply your results by this value Use this formula for the conversion 10 n 20 where n is the dB offset If you place the value 1 413 for this example in K1 define the function as SPEC K1 9 68 Key Reference Meas Restart hardkey Meas Restart hardkey Press this hardkey to restart a measurement When you restart a measurement the following things must take place in the order listed before the analyzer begins taking data 1 The measurement hardware must settle 2 The trigger conditions must be met The beginning of data collection is different for each of the following setups Swept spectrum and autosweeping selected The analyzer begins sweeping at
125. f Marker On Noise Lvl Off DISPLAY group ctive Trace hardke ormat hardkey Active Trace A Display Format Single Graticule On _ Meas Da cale hardke Trace A Input Spectrum Vertical Div 10 dB Trace B Input Spectrum Ref Track On Trace Title A default Trace Title B default Trace Type Log Magnitude 9 96 Key Reference Preset hardkey MEAS UBEDENT Too PREE Hold option Dfi Number Averages 10 Res B BW 17 KHz Vid Fitr Off BW Coupie On Zoom Type Hi Accrcy Zoom Swen Auto l Manual Freq 75 05 MHz Sweep Time 260 8 ms Sample Time 4 us Oversweep On Center 75 05 MHz Span 149 9 MHz Start 100 0 kHz Stop 150 0 MHz Step Size Auto User Step Size 1 kHz Sign Trk OFF pa On Input Impedance 50 Q 1 Meg Ref Imped 50 Q Source State Off Source Amplitude 10 0 dBm Amplitude Step 0 1 dBm Output Z 50 Q Z Coupling On Trigger Type Free Run Arm Auto 9 97 Key Reference Preset hardkey SYSTEM group i Local HP 18 hardkey Disk Utit bardkey Format Option O interleave Factor 1 Catalog Off Trace A Pen 2 Trace B Pen 3 Marker A Pen 5 Marker B Pen 6 Alpha Pen 4 Graticule Pen 1 Trace A Line Type Solid User Defined line A 4096 Trace B Line Type Solid User Defined line B 4096 Plot Speed Fast 50 cm s User Defined speed 50 cm s Page Eject On Spel Fetn hardkey Auto Cal On Beeper On Srce 10dB Out S
126. f any electrical instrument in such an environment constitutes a definite safety hazard KEEP AWAY FROM LIVE CIRCUITS Operating personnel must not remove instrument covers Component replacement and internal adjustments must be made by qualified maintenance personnel Do not replace components with power cable connected Under certain conditions dangerous voltages may exist even with the power cable removed To avoid injuries always disconnect power and discharge circuits before touching them DO NOT SERVICE OR ADJUST ALONE Do not attempt internal service or adjustment unless another person capable of rendering first aid and resuscitation is present DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT Because of the danger of introducing additional hazards do not install substitute parts or perform any unauthorized modification to the instrument Return the instrument to a Hewlett Packard Sales and Service Office for service and repair to ensure the safety features are maintained DANGEROUS PROCEDURE WARNINGS Warnings such as the example below precede potentially dangerous procedures throughout this manual Instructions contained in the warnings must be followed Warning Dangerous voltages capable of causing death are present in this 7 instrument Use extreme caution when handling testing and adjusting LA eackarn SAFETY SYMBOLS General Definitions of Safety Symbols Used On Equipment or In Manuals Instruction manual s
127. formed or adhered to could result in damage to or destruction of part or all of the product Note The NOTE sign denotes important information It calls attention to procedure y practice condition or the like which is essential to highlight Table of Contents Chapter 1 Before You Begin Howto Use GUS BOOK 6 x sek eee AE A A RA A A ii 1 1 Are you using the correct book ai A Bed A A 1 1 Hardkeys and Softkeys AA de we Seal Bt alee ws Se SLA ale RRSP SAE S toto aes 1 2 Where to find Additional Information cee eee eens 1 3 Using he HBS J key AAA th hai ot AoAo 1 3 The Getting Started Guides sete a a ge a 1 3 Other Information A aa ein hd a tad we BE We Bee re th Accel eee a 1 3 ADOUL the Analyzer E di hte e id Tas hr 1 4 Chapter 2 Front Panel Overview Input 2 2 putas ao aake ad s tae A Shoal 30s Stee Mo ee eta Saha ok 2 1 AO PATAS Hi ASA A Sed ow a es GR a A Input Over Range RNG 622 2 2 ow 5 sels ee base aii Ble a eed 2 3 Input Overload OVED ii 6 eda AA hate ad SORE Hehe a 2 3 E A A O E Bata 2 4 The SOSA LOPE A E e a ada 2 4 PMN 759 Input A ge wig ect See E a ee ena Bone snes aie e a aed seal a4 he we 2 4 LES LMAO Inp t Sid so are tga a Sed ete et as eh add 2 5 Active Probe Power Connector as A ilo BA Ge led Bla 2 6 SOUTES wa ai ste Hie a we ae ae Bg eae Pater a wo hai te he oc ee ewe eh 2 7 DUS VG i Bn hs cere e a e Grae ees ais ete ee cede NG sce BS ea 2 9 FOWE SWEERS ia EA ners A bs ah d
128. ftkey Key Path User Define gt EDIT Press END EDIT when you have finished editing or viewing your program When you press END EDIT you are returned to the main HP Instrument BASIC menu You can RUN the edited program immediately but it is best to save your changes first Note You must save or resave an edited program or the changes will be lost when you y turn the analyzer off END LINE softkey Key Path User Define gt UTILITIES gt SECURE Before you secure an HP Instrument BASIC program protect it against viewing you must specify the range of lines you want to secure Press END LINE to specify the last line in the range An entry box is displayed so you can enter a new value After you have specified the first and last lines press PERFORM SECURE to secure those lines and all lines that fall between them When you edit or print a secured line you will see an asterisk rather than program statements after the line number 9 33 Key Reference ENTER softkey program edit ENTER softkey program edit Key Path User Define gt EDIT or User Define gt EDIT gt TYPING UTILITIES Press ENTER to accept the changes you ve made while editing a line of your HP Instrument BASIC program If the editor detects no syntax errors the line is accepted Note If you move the text cursor off of the line before you press ENTER the changes
129. ge 0 dBm ref level 5 dBm s Range Input range 10 dBm a Result Ref level 15 dBm The setting of REF TRACK ON OFF is ignored for the following kinds of trace data a Constants w Data registers includes recalled traces When tracking is turned off or when it is being ignored you must use the REFERENCE LEVEL softkey to explicitly set the reference level 9 107 Key Reference REFERENCE LEVEL softkey REFERENCE LEVEL softkey Key Path Scale Press the REFERENCE LEVEL softkey when you want to reposition the active trace along its vertical axis To lower the trace increase the reference level value Reference level defines the upper limit of the active trace box It defines this limit using linear units Vrms or logarithmic units dBm depending on the coordinate system being used Use options under the Trace Type hardkey to select a coordinate system Note You can link the trace box s upper limit to the current input range by turning on t reference level tracking Rename File softkeys Key Path Disk util rename file just displays a menu The menu contains all the softkeys you need to rename a file w ORIGINAL FILENAME prompts you for the file s current name NEW FILENAME prompts you for the file s new name m PERFORM RENAME renames a file based on your entries in the two filename prompts When you press PERFORM RENAME the analyzer renames a file on the defaul
130. h Save Recall gt RECALL MORE Use RECALL UPPER LIM to recall a limit line into the upper limit register of the active trace The limit line is recalled from the default disk unless you include a disk specifier in the filename prompt Hint You can create a limit from a trace Just save the trace with SAVE TRACE then recall it with RECALL UPPER LIM or RECALL LOWER LIM When you recall an upper limit you are prompted for a filename If the catalog is off the prompt contains a default filename U_LIM If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys 9 106 Key Reference REF TRACK ON OFF softkey REF TRACK ON OFF softkey Key Path Scale The REF TRACK ON OFF softkey toggles reference level tracking on and off for the active trace Reference level defines the upper limit of a trace box When tracking is turned on this upper limit is tied to the current input range Each time the range changes the upper limit of the trace box changes to match You can still use REFERENCE LEVEL or AUTO SCALE to change the reference level while tracking is on Ifyou do this the analyzer remembers the resulting offset between the input range and reference level Then if the range changes the analyzer reestablishes the offset Here s an example a Initial conditions Ref tracking on input ran
131. igures the analyzer to make the lowest distortion measurement possible No other adjustments are necessary Although low distortion mode lets you make the lowest distortion measurement possible it cannot eliminate the possibility that the analyzer may contribute very small amounts of distortion to your measurement To learn about the maximum distortion that the analyzer may contribute see the HP 3588A s published specifications Additional Considerations Here s what else you should know a When you turn on the low distortion mode the analyzer s noise floor increases However you can offset this increase by narrowing the resolution bandwidth swept spectrum measurements or by selecting high resolution zoom narrow band zoom measurements w Low distortion mode is not available when using the analyzer s IMQ input You can t toggle to AUTORANGE ON OFF while in low distortion mode However you can perform a single autorange by pressing SINGLE AUTORANGE 7 10 Manual Sweep Introduction For swept spectrum measurements sweep times can be very long for small spans particularly when using a narrow resolution bandwidth If you press Sweep and then toggle to SWEEP AUTO MAN you can disable the analyzer s automatic sweep and enable manual sweep Manual sweep lets you tune the analyzer to a discrete frequency This lets you measure the amplitude of discrete frequencies without waiting for the analyzer
132. ilar effect 9 127 Key Reference Spel Fetn hardkey Spcl Fctn hardkey Spel Fetn groups infrequently used softkeys under one hardkey The softkeys allow you to do the following things Calibrate the analyzer Turn the beeper on and off Set the battery backed clock s time and date Display your analyzer s serial number Enable special hardware setups during performance tests SPECTRUN softkey Key Path Math gt DEFINE Fx When you are defining a function press SPECTRUM to specify calibrated input data as an operand The abbreviation SPEC is added to the end of the definition See also Operand Menu SQRT NBW softkey Key Path Math gt DEFINE Fx When you are defining a function press the SQRT NBW softkey to select the square root of the noise equivalent bandwidth as an operand The abbreviation SQRT NBW is added to the end of the definition To generate a power spectral density trace you can divide the power value at each point of the input spectrum by the square root of the current noise equivalent bandwidth This normalizes power values so that they approximate the values obtained with a 1 Hz resolution bandwidth See also Operand Menu Note The noise bandwidth for the current measurement is noted in the setup state 4 9 128 Key Reference START and STOP softkeys START and STOP softkeys Key Path Freq Use START and STOP tog
133. ile softkeys Display Format softkey group BASIC Key Path User Define gt display format The softkeys in this group allow you to specify which part of the analyzer s screen should be used for HP Instrument BASIC programs Program statements such as PRINT MOVE and DRAW require that some portion of the display be allocated for their use OFF allocates no display area to your program FULL allocates to your program that portion of the display used by a full height trace box The full display is 29 text rows high and 58 columns wide The lower left corner for MOVE and DRAW is 0 0 The upper right corner is 475 355 m UPPER allocates to your program that portion of the display used by the upper half height trace box The upper display is 14 text rows high and 58 columns wide The lower left corner is 0 0 The upper right corner is 475 173 LOWER allocates to your program that portion of the display used by the lower half height trace box The lower display is the same size as the upper display Divide softkey See Operator Menu 9 28 Key Reference Display Format softkey group Display Format softkey group Key Path Format Use the Display Format softkey group to select one of three formats for trace display or to select a summary of the current instrument setup m SINGLE displays only one trace the active trace using a single full height trace box mw UPPER LOWER
134. in compression or distortion products in excess of the analyzer s published specifications Simply reduce the input signal or change to a less sensitive input range if possible Note Over range is a sensitive to broadband signals that is it will be triggered even if the over range frequency component is outside the analyzer s current frequency span Thus the RNG indicator may appear even if you re viewing a frequency span with no over range components input Overload OVLD Overload occurs when the input signal is strong enough to overload the analog to digital converter in the analyzer s IF stage When this happens the OVLD status indicator appears at the lower right hand corner of the screen The analyzer s response to an overload condition OVLD is similar to an over range condition RNG If autoranging is on the analyzer autoranges if possible OVLD lets you know that the analog to digital converter in the analyzer s final IF is overloaded When this happens there may be significant distortion and your measurement data can be seriously compromised To fix an OVLD condition simply reduce the input signal or change to a less sensitive input range if you can Note Unlike an over range condition OVLD occurs only for signals that are within the e currently selected frequency span This is because the OVLD detector monitors the analog to digital converter at the analyzer s IF stage Out of band signals are not det
135. ing N equal to 5 Here the new sweep data is weighted by 1 5 and the current data by 4 5 In this case each sweep can make a considerable difference to the trace If you change the input signal the displayed trace will show these changes much more quickly Measurement Enhancements Peak Hold Peak Hold When you turn on the peak hold function the analyzer shows the maximum amplitude value recorded for each point in the display The analyzer updates these results after each measurement and continue to do so until you turn off peak hold Peak hold is a convenient way to measure the frequency drift of a particular spectral component You might want to zero the offset marker at this frequency component when you first turn on peak hold this makes it easier to find the point where the signal drifted from By the way do not confuse peak hold with peak track or signal track Peak hold provides the maximum values at each display point Peak track moves the main marker to follow the largest signal see chapter 6 Marker Functions And signal track changes the center frequency to follow a changing signal Signal Track Like the peak hold feature signal track is also useful when measuring drifting signals But signal tracking doesn t just show how far a peak has drifted it actually changes the analyzer s center frequency to follow the drifting signal When you turn on signal track the analyzer changes its center frequency automatically
136. ing trace graticules The graticule pen is also used for the borders around the instrument state and the disk catalog Hardkeys There are five groups of hardkeys on the analyzer s front panel DISPLAY MARKER MEASUREMENT Numeric entry SYSTEM The keys in these groups are referred to as hardkeys because the function assigned to each key never changes except during alpha entry and program editing In contrast the function assigned to each softkey can change A hardkey label is printed directly on each hardkey The label tells you which function is assigned to that key In the help text hardkeys are represented by surrounding hardkey labels with braces for example The Help hardkey is used to An engraved letter appears at the lower right corner of most hardkeys This letter tells you which alpha character will be inserted to the left of the text cursor when you press a hardkey during alpha entry or program editing 9 47 Key Reference Help hardkey Help hardkey For help on a hardkey or softkey except Preset Press the key To display a cross referenced topic Turn the knob if necessary until the link is highlighted then press 4 To access any other Help function Press the appropriate number key For example press 6 to go to the next page Numbers are mapped as follows Print Previous Previous Topic Page Topic Page f index s Qui e Many help topics contain
137. inserted ahead of the END statement If the program buffer already contains a program OUTPUT statements are inserted ahead of the program line containing the text cursor You can position the text cursor by pressing EDIT and then turning the knob You can not record the following front panel operations a Redefinition of the analyzer s controller capabilities HP IB commands are not allowed to do this Saving or recalling of HP Instrument BASIC programs A program cannot be saved or recalled while it is running Any other HP Instrument BASIC operation These operations are all grouped under the User Define hardkey which disables keystroke recording 9 32 Key Reference END EDIT softkey The recorded version of a few front panel operations may require additional programming usually to synchronize program execution with the analyzer s measurement sequence Here is an example During manual arming any attempts to arm the analyzer before it is ready are ignored When you operate the analyzer from the front panel you can simply wait until the WAITING FOR ARM message is displayed and then press ARM If you record this operation you must add a routine that simulates your waiting for the message The routine should check the RDY_FOR_ARM bit in one of the analyzer s registers and hold off the ARM command until the bit is set See your HP Instrument BASIC manual for more information about synchronization END EDIT so
138. is 0 1 dB You can change the amplitude in the usual ways but with the following enhancements m You can control the sensitivity of the knob and arrow keys with AMPLITUDE STEP a Yov can set source amplitude to the marker s current y axis value with Marker Value Note If the 75Q output impedance is selected the actual amplitude will match the entered amplitude only if you remember to use the 25Q adapter barrel supplied with the analyzer Source hardkey The softkeys grouped under the Source hardkey are used to control the analyzer s tracking source sometimes called a tracking generator The softkeys allow you to do the following things a Turn the source on and off m Change the output amplitude a Select the output impedance Reset the source s protective relay The source s sinusoidal output follows or tracks the receiver s tuned frequency Because the receiver is tuned differently in the following measurements the source frequency is controlled differently for each m Swept spectrum The source frequency sweeps through the specified frequency band at the same rate as the receiver s tuned frequency m Manual sweep The source frequency tracks the current manual sweep frequency a Narrow band zoom The source frequency is fixed at the analyzer s center frequency Note Source output between 0 and 150 MHz is possible but performance below 10 Hz is g not specified 9 125
139. ives you access to special characters during program editing When you press one of these softkeys the characters listed after INSERT are displayed in a menu You can then insert one of these characters to the left of the text cursor by pressing the corresponding softkey A O AN Note A CANCEL RETURN softkey is displayed so you can return to the Typing Utilities menu without inserting a special character INSERT KEYWORD softkey Key Path User Define gt EDIT gt TYPING UTILITIES The INSERT KEYWORD softkey allows you to insert complete keywords to the left of the text cursor when you are editing a program Here s how you insert a keyword 1 Press INSERT KEYWORD J 2 Press the hardkey whose engraved letter corresponds to the first character of the keyword you want 3 Locate the keyword in the resulting menu If more than nine keywords begin with the same character you may need to press a MORE softkey to locate the keyword you want 4 Insert the keyword in your program by pressing the corresponding softkey nace re o e Note A CANCEL softkey is displayed so you can return to the Typing Utilities menu without inserting a keyword aaa 9 54 Key Reterence INSERT LINE softkey INSERT LINE softkey Key Path User Define gt EDIT Press INSERT LINE to enable and disable insert line mode when you are editing an HP Instrument BASIC program When the editor en
140. key PLOT ALL PLOT TRACE PLOT MARKER PLOT OFFST MKR PLOT GRATICULE DEFINE PLOT DEFINE PLOT PENS DEFAULT PENS TRACE A PEN TRACE B PEN MARKER A PEN MARKER B PEN ALPHA PEN GRATICULE PEN TRACE A LINE TYPE SOLID DOTTED DASHED USER DEFINED USER LINE TYPE TRACE B LINE TYPE PLOT SPEED SLOW 10 cm S FAST 50 cm S USER DEFINED USER PLOT SPEED PAGE EJCT ON OFF PRINT ALL Spel Feta hardkey SINGLE CAL AUTO CAL ON OFF BEEPER ON OFF TIME HHMM DATE MMDDYY J SERIAL NUMBER PREM TESTS CALIBRATR TO INPUT SRCE 10dB IN OUT SRCE 20dB A IN OUT SRCE 20dB B IN OUT SRCE DAC ATTEN 10 10 index A PO ak TTT TTT IS PUA SP SAPARD A absolute marker See main marker active entry See numeric entry keys active probe 2 6 active trace See display alpha entry keys 2 23 9 3 alpha entry mode 2 23 9 3 arrow keys 2 22 autoranging 2 2 9 7 during scalar network measurements 7 2 averaging See video averaging bandwidth coupling 4 5 9 10 changing 4 5 disabling 4 9 preset 9 11 beeper 9 8 C calibration automatic 9 5 center frequency and zero span 9 13 controller capability 9 16 See also HP IB copy operations disk copying 9 17 file copying 9 17 CRT cleaning See display CW mode See manual sweep D data collection See measurement restart data registers See
141. knob The knob is assigned to move the marker unless a numeric entry box is displayed However you must select MARKER X ENTRY if you want to move the marker by pressing the arrow Keys or by entering a value with the number keys If you turn the knob slowly or press an arrow key one time the marker moves by one display point If you use the number keys you can either move the marker to a particular display point number 0 400 or to a particular frequency or time depending on the current x axis units Note When you enter a frequency the marker is moved to the display point containing y that frequency Frequency values are bounded by the current start and stop frequencies Time values used only when zero span is selected are bounded by 0 seconds and the current sweep time 9 67 Key Reference Marker search keys Marker search keys Four softkeys allow you to search for peaks on the active trace MKR gt PEAK Finds the highest peak once NXT RIGHT PEAK Finds the closest peak to right of marker NXT LEFT PEAK Finds the closest peak to left of marker PEAK TRK ON OFF Finds the highest peak each time trace updates A peak is a local maximum on a trace The slope of a trace is positive to the left of a peak and negative to the right In addition the slope on one side of a peak must not change for at least one vertical division one half division if the display format is upper lower Math hardk
142. level of random noise appears to increase This effect is more pronounced for longer sweep times When the analyzer spends more time sweeping there is an increased probability that it will detect more positive excursions of the noise Hint Use the noise level function to measure the true energy of the noise floor 9 86 Key Reference PEAK HOLD softkey PEAK HOLD softkey Key Path Avg Pk Hid Press PEAK HOLD when you want the analyzer to maintain the peak value of each display point over the course of several measurements When PEAK HOLD is selected the results of a completed measurement are compared point by point with currently displayed trace The maximum value of each point is retained and displayed in the updated trace Note Peak hold is purely a display function The maximum value of each point is not reset when you change the analyzer s measurement parameters To reset the displayed data you must turn peak hold off and back on Peak hold is especially useful for detecting transient signals It is also useful for observing a signal whose frequency changes over time PEAK TRK ON OFF softkey Key Path Marker Fetn Press PEAK TRK ON OFF to enable and disable the analyzer s peak tracking function When peak tracking is on the analyzer automatically positions the main marker on the largest peak of the active trace each time the trace is updated The marker readout reflects any changes in the ma
143. lue with one important exception the y numeric entry softkey s entry box must be displayed before you turn the knob Some numeric parameters can also be changed using the Marker Value hardkey If a parameter can be changed in this way it is noted under the softkey description CLEAR ENTRY softkey Press this softkey to delete all characters from a text string during alpha entry CLEAR INP TRIP softkey Key Path Range input Press the CLEAR INP TRIP softkey to reset close the analyzer s input protection relay The input protection relay is tripped opened if the signal level at the INPUT connector is significantly above the maximum input range A message on the screen tells you when the relay has been tripped CLEAR SCREEN softkey Key Path User Define gt DISPLAY FORMAT Press this softkey to clear the portion of the screen allocated to your HP Instrument BASIC program 9 14 Key Reference CLEAR SRCE TRIP softkey CLEAR SRCE TRIP softkey Key Path Source Press the CLEAR SRCE TRIP softkey to reset close the analyzer s source protection relay The source protection relay is tripped opened if the signal level at the SOURCE connector is significantly above the maximum source amplitude or if excessive de voltage is present A message on the screen tells you when the relay has been tripped CONFIRM DELETE softkey Key Path Marker Fetn gt LIMIT TEST gt DEF
144. marker readout is labeled Cntr and its x axis value is highlighted The frequency counter only counts data from the current input spectrum If you select trace data that is not linked to the input spectrum for example the contents of a data register no count value is displayed 6 6 Marker Functions Noise Level Noise Level Overview For swept spectrum measurements you can use the noise level function to measure noise density To make a noise level measurement press Marker Fetn and toggle to NOISE ON OFF J After you turn on the noise level function the marker readout indicates rms noise spectral density normalized t a 1 Hz bandwidth at the main marker position When the offset marker is on the noise level readout is relative to the offset marker position During swept spectrum measurements the analyzer sweeps to the marker position measures the noise level and then completes the sweep The noise density measurement is independent of the current resolution bandwidth sweep speed or frequency span If you ve selected manual sweep the analyzer simply measures noise at the current manual frequency Special Considerations The following conditions must be met before the analyzer can accurately measure noise level a The noise you are measuring must be random noise The analyzer s resolution bandwidth must be narrow enough to exclude any discrete signals such as tones from the noise measurement
145. ment 9 132 Key Reference Sweep hardkey Sweep hardkey The Sweep hardkey displays a menu Use the softkeys in this menu to control the analyzer s sweep across the band of frequencies you are analyzing The Sweep menu contains the following softkeys m sweep auto man lets you enable and disable manual sweeping MANUAL FREQ lets you specify the measurement frequency during manual sweeping m SWEEP TIME lets you control the amount of time it takes to complete an automatic sweep m SAMPLE TIME lets you control the amount of time it takes to measure a single frequency during manual sweeping m OVERSWEEP ON OFF lets you enable and disable oversweeping Note These softkeys are not used for narrow band zoom measurements they are only y used for swept spectrum measurements 9 133 Key Reference SWEEP TIME softkey SWEEP TIME softkey Key Path Sweep Sweep time specifies how much time the analyzer takes to complete a sweep when automatic sweeping is selected When you press the SWEEP TIME softkey an entry box is displayed so you can enter a new time Automatic sweeping works one of two ways u For all measurements except zero span The analyzer sweeps its local oscillator LO through the specified frequency band in the amount of time specified by SWEEP TIME For zero span measurements The analyzer samples the amplitude of the current center frequency over the amount of tim
146. mple task to learn how to step the manual frequency 8 4 Manual Sweep Stepping the Manual Frequency SAMPLE TASK Stepping the Manual Frequency over a Wide Span This task demonstrates how to step the manual frequency to measure equally spaced signals in a wide span In the example here we ll characterize the harmonics of a 1 MHz signal using manual sweep After the initial setup this type of measurement can be performed in several seconds but a comparable measurement using automatic sweep would take over a minute 1 Press Preset 2 Connect the signal source to the analyzer s input 3 Press Freg Use the START STOP or SPAN softkeys to select an appropriate frequency span 4 Press Res BW and select a resolution bandwidth of 290 Hz 5 Press BW COUPLE PRESET 6 Press Marker MKR gt PEAK 8 5 Manual Sweep Stepping the Manual Frequency 7 Press Marker Fetn J Then toggle to FREQ CNTR ON OFF 8 Press Freg Toggle to STEP SIZE AUTO USER Press USER STEP SIZE Marker Value 9 Press Sweep Then press MANUAL FREQ Marker Value 10 Press Marker Fein Then toggle to FREQ CNTR ON OFF 11 Toggle to SWEEP AUTO MAN J 12 Press Res BW and select a resolution bandwidth of 290 Hz 8 6 Manual Sweep Stepping the Manual Frequency 13 Press Sweep again Now use the arrow keys to step
147. n for maximum accuracy use the frequency counter To learn more about the frequency counter see Frequency Counter later in this chapter To learn more about display resolution and frequency resolution see the sidebar on peak detection in chapter 4 Swept Spectrum Measurements Marker Functions Marker to peak Marker to peak To locate the frequency component with the greatest amplitude press MKR gt PEAK The analyzer then moves the main marker to this peak Marker to next right peak Marker to next left peak Press NXT RIGHT PEAK to move the main marker to the next peak to the right of the current marker position Press NXT LEFT PEAK to move the main marker to the next peak to the left of the current marker position The next right peak or next left peak must be a minimum distance from the current marker location and a minimum height above the noise floor These minimums are defined by a peak search algorithm If the requirements of the algorithm are not met the marker doesn t move Autoscaling is sometimes necessary to reveal additional peaks Marker Functions Marker to center frequency Marker to center frequency Press MKR gt CTR FREQ to make the current main marker position the new center frequency To place the center frequency more accurately turn on the frequency counter before pressing MKR gt CTR FREQ When the counter is on the analyzer uses the counter fre
148. n In either case you might want to step through some of the sample measurement tasks outlined in the HP 35884 Getting Started Guide if you haven t done so already If swept spectrum measurement type is not already selected simply press Preset this is the green hardkey Since swept spectrum is the default setting the analyzer is always operating as a swept spectrum analyzer after you ve preset the instrument Alternatively you can switch to swept spectrum by pressing Meas Type and then pressing SWEPT SPECTRUM 4 1 Swept Spectrum Measurements Swept Spectrum Measurements Oversweep Oversweep Unlike traditional swept tuned analyzers that use analog IF intermediate frequency filters the HP 35884 uses digital IF filters These digital filters settle in a more predictable way than comparable analog filters This means the analyzer can make faster measurements particularly at narrow resolution bandwidths than spectrum analyzers with analog IF filters The inherent predictability of digital IF filters allows the HP 3588A Spectrum Analyzer to use a built in correction algorithm to oversweep its digital filters yet still maintain both amplitude and frequency accuracy This allows the analyzer to sweep even faster up to four times faster than conventional swept tuned analyzers for comparable measurements Oversweep is useful for most measurement situations and is automatically turned on when you turn on the
149. n eed eee oad ae tine wie 2 10 PEAALOMEYR ANU SORRENTO leeds Me A ah ea ernie eens 2 11 A A ay Sits ga tac e BS O88 ae Div Soden cased maae Bat aces peel cette 2 12 NASA A o as ob dase Gen achat os A edo 2 12 Marker Readout is atta ih Feats a ei as One wider Xo Slick A A 2 13 Status Indicator Area ea Awe o a Niet ico eee Aan ate 2 14 Trace Box A and Trace Box BD 2 rt SRD Ree tate ele Me a 2 15 Fop Gp Mecsas Alea stato ls alee a oa wal 2 16 NOUS NOON A Sur wih a gid a eee Cee ako Aa ee oe 2 16 O tented tea eels ile Mie tn SoD el hata ol ce ne ke chums dm Ngee et 2 17 Status Message Area A a Se Ned cn Rah a edd 2 18 race Tiler is A a he eek aw tae es 2 18 CRT Cate and CICAD 2 19 Marker Keys and Knob Tt iras dt dit 2 20 The Markor EV Sepia nadaa ao cas Ele aio 2 20 TEE EIOD Sp stn eke hiss pte O A 2 20 Table of Contents Continued Numere ENity Keys orang Te ESA RRA eet A RA OE a ETET 2 21 Active Entry ise ene Vata A e a ene eS S 2 21 ThE ATTOW Keys ua ds E aie wake a al aaa es 2 22 Alpha Entry Revs e cea auni a be aay ch E RA DA Pie eS a ARA A Sd ds a 2 23 Measurement Keys es gar d aese e A AA E A ec ns 2 24 Display Keys 3 5100 ooh EAS AA AA Ah A A AA A 2 25 System Keys escri as io ot eo 2 26 The Preset Key AAA AA A A A AA ASAS A SO 2 27 Phe Helo Key ra 5 dig whe Botner ee due A AS ak ga ale AA Me ea 2 31 Chapter 3 Rear Panel Overview Fuse Voltage Selector and Line connector AGREE 3 1 HP IB connecto
150. nding on your current measurement situation Absolute limits always remain at a fixed amplitude Use an absolute limit for example to make sure a test signal does not exceed a specific amplitude Relative limits on the other hand are not tied to a specific amplitude If you make a limit relative its position on the screen does not change when you change the reference level You can use a relative limit for example to check the relative levels of a test signal s harmonic distortion or to check the shape but not the insertion loss of a filter 6 10 Measurement Enhancements Scalar Network Measurements Introduction You can use the analyzer s built in source to make swept frequency response measurements This is a good way to characterize the amplitude versus frequency response of filters amplifiers and other electronic devices To learn more about making scalar network measurements and to step through a sample measurement task see the HP 35884 Getting Started Guide Note The HP 3588A Spectrum Analyzer performs scalar amplitude only network t measurements You cannot use the analyzer to make phase measurements 7 1 Measurement Enhancements Special Considerations for Scalar Network Measurements For successful scalar network measurements with the HP 3588A Spectrum Analyzer be sure to do the following a Turn Off Autoranging Press Range Input and then toggle to AUTORANGE ON OFF If you don t t
151. ne the frequency band If the current value falls outside the new band it changes to the closest available value within the band MARKER A PEN softkey Key Path Piot Print gt DEFINE PLOT gt DEFINE PLOT PENS Press MARKER A PEN to specify which plotter pen should be used for plotting trace A s main and offset markers The marker A pen is also used to plot the x and y axis coordinates of trace A markers when you use the PLOT MARKER and PLOT OFFST MKR softkeys and to plot limit lines 9 64 Key Reference MARKER B PEN softkey MARKER B PEN softkey Key Path Plot Print gt DEFINE PLOT gt DEFINE PLOT PENS Press MARKER B PEN to specify which plotter pen should be used for plotting trace B s main and offset markers The marker B pen is also used to plot the x and y axis coordinates of trace B markers when you use the PLOT MARKER and PLOT OFFST MKR softkeys and to plot limit lines Marker Fctn hardkey The Marker Fetn hardkey displays a menu You use the softkeys in this menu to control special marker functions in the active trace The marker readout is displayed directly above the trace box Note Basic marker functions are available under the Marker hardkey 4 The analyzer s special marker functions allow you to do the following things Automatically position the main marker on the largest peak each time a trace is updated Use a count
152. nge the analyzer selects a more sensitive range Note If you change the range manually autoranging is turned off y Continuous autoranging is not available when low distortion mode is enabled or when the 1 megohm input impedance is selected However single autoranging is available for low distortion mode Note Turn autoranging off when you are making a scalar network measurement Y Key Reference Avg Pk Hid hardkey Avg Pk Hid hardkey Press this hardkey for access to the analyzer s video average and peak hold functions Both allow you to combine the results of several measurements in one trace VIDEO AVERAGE and PEAK HOLD like all other softkeys in bracketed groups are mutually exclusive You can t select them both at the same time Select OFF if you don t want either function to be active Back Space hardkey Use Back Space to correct mistakes in the following situations When entering or editing a text string Press Back Space to delete the character to the left of the cursor a When entering a number Press Back Space to delete the last digit of the number When defining a math function Press Back Space to delete the last operator or operand in the definition BEEPER ON OFF softkey Key Path Spel Fetn Press BEEPER ON OFF to enable and disable the analyzer s beeper An enabled beeper emits an audible tone when some messages are displayed Also if
153. nt states Limit definitions Math definitions HP Instrument BASIC programs Note To rename copy or delete files use the softkeys grouped under Disk Util The analyzer can access files on one of three disks although one of these disks is optional Non volatile RAM disk Volatile RAM disk a Internal disk optional Caution The volatile RAM disk is cleared each time you turn the analyzer off Copy important files to another disk before power down or they will be lost The analyzer displays a prompt and enters alpha entry mode when it s time to identify the file you want to save or recall Use the default filename displayed in the prompt or modify the name with the alpha entry keys When the filename is correct press enter to start the save or recall operation You can do two things to simplify save and recall operations a Designate the disk you use most often as the default disk x Display the disk catalog You only need to enter a filename to identify a file on the default disk You must enter a disk specifier and a filename to identify a file on any other disk When the catalog is displayed you don t need to type the name of a file you want to recall or overwrite Instead you can just select the file with the knob before bringing up the filename prompt The name of the file you select is automatically placed in the prompt 9 118 Key Reference Scale hardkey Scale hardkey
154. nter on before you use MKR gt CTR FREQ Or Marker Value to change the value of a frequency parameter The analyzer will use the counted frequency rather than the less accurate display point frequency for the parameter s new value Hint If the count seems inconsistent at frequencies below 100 kHz decrease the resolution bandwidth The presence of the second mixer image in the third IF makes this necessary During swept spectrum measurements the analyzer sweeps to the marker position counts and then completes the sweep If manual sweeping is selected the analyzer just counts at the manual frequency During narrow band zoom measurements the analyzer completes one measurement and then counts When a count has been completed the marker readout is labeled Cntr and its x axis value is highlighted The frequency counter only counts data from the current input spectrum If you select trace data that is not linked to the input spectrum for example the contents of a data register no count value is displayed The following trace data is linked to the current input spectrum a An input spectrum s normalized spectrum A function definition that uses an input spectrum contains the abbreviation SPEC 9 41 Key Reference Freq hardkey Freq hardkey The Freq hardkey displays a menu You use the softkeys in this menu primarily to select the band of frequencies or in the case of zero span th
155. o Averaging Overview Special Considerations Peak Hold Signal Track Modifying the Step Size Locating signals quickly by stepping CENTER FREQUENCY SAMPLE TASK Modifying step size to position the center frequency Low distortion mode Overview What does it do Additional Considerations e z bsol t s o 4s Special Considerations a amp 8 rr a gt a aana o v ssa b a a 4 8 6 ew ew of 4 t o a lt s e s a 9 2 gt soaa we s ea a a e o o 4 7 8 as 40 gt es He osale lt s too 4 t b o e s s gt gt e gt we e o oo ww t gt o ro 4t o gt 74 a a s t a o 0 a a 4 a 0 2 o Re 4 o t t eo eoo s oo ee 0 se voss A so eassa too eee eo ee se ee 4 4 4 oo Py gt 4 Soi So Sid ad ab ethane Gas Bs Orca IS ene Mee Dock ta a 7 10 ee no o 4 o a o 0 4 e 0 0 oe we we 0 iif Table of Contents Continued Chapter 8 Manual Sweep n AIQUOCUCUON al E DAA AA AA A o AA a 8 1 Using Manual SWED rsa ea A ARA AI AS A ee 8 2 Special Considerations for Manual Sweep ooooooocoooo ee ee oo 8 3 The Manual Me
156. oftkey BW COUPLE PRESET softkey Key Path Res BW Press BW COUPLE PRESET to restore the optimum relationships between the following parameters even when bandwidth coupling is disabled u Frequency span Resolution bandwidth m Video bandwidth Sweep time The optimum relationships provide the best compromise between frequency resolution and speed for most swept spectrum measurements Note The analyzer automatically maintains the relationship between coupled parameters y if you enable bandwidth coupling The optimum relationships between coupled parameters follow m resolution bandwidth RBW span 100 w video bandwidth RBW 1 54 a sweep time span RBW 2 2 with oversweep on a sweep time span RBW 2 2 with oversweep off When the analyzer cannot realize the optimum RBW it selects the next largest available RBW When it cannot realize the optimum sweep time it selects the shortest available time that can provide calibrated measurement results 9 11 Key Reference CATALOG ON OFF softkey CATALOG ON OFF softkey Key Path Save Recall or Disk Util This softkey toggles the disk catalog on and off The catalog describes the contents of the default disk in a tabular format The catalog header includes the disk s volume name formatting time and date and available space The file descriptions include each file s name size in bytes and type They also include each file s
157. oint of a segment MOVE ALL VERTICAL This lets you alter the amplitude value of all endpoints at once DELETE ALL This deletes all segments at once DELETE SEGMENT This deletes the segment that is vertically aligned with the limit marker 9 24 Key Reference DELETE ALL FILES softkey After you define an upper limit it is maintained in a limit register The amplitude values of the limit are maintained without units so they assume the amplitude unit of the current display the unit used for the reference level Hint You can also create an upper limit from a trace Just save the trace with SAVE TRACE then recall it with RECALL UPPER LIM DELETE ALL FILES softkey Key Path Disk util Press DELETE ALL FILES to remove all files from one of the disks The files are deleted from the default disk unless you change the disk specifier in the prompt Hint To remove just one file from the disk use the DELETE FILE softkey When you press DELETE ALL FILES you are prompted to enter the disk specifier of the disk you want to clear The specifier of the default disk is automatically placed in the prompt but you can change it with the alpha entry keys Note When you press the ENTER softkey to complete entry of a disk specifier the disk is cleared without further prompting Be sure the name is correct before pressing ENTER DELETE ALL softkey Key Path Marker Fetn gt L
158. om a particular function can be displayed by selecting the g corresponding Fx softkey under the Trace Data hardkey A trace math function is used to add subtract multiply or divide some combination of the following measurement data stored trace data constants and other functions The analyzer does some limited tracking of units during these operations A function is defined via two alternating menus an operand menu and an operator menu The menus alternate in a manner that allows you to define the function in standard algebraic notation All math operations are performed on linear rather than logarithmic data Since you cannot create functions that add or subtract logarithmic values you must create equivalent functions that multiply or divide linear values This is why a normalized spectrum is defined as SPEC D8 Suppose you want to add 3 dB to your measurement results Just convert the logarithmic offset to its linear equivalent and multiply your results by this value Use this formula for the conversion 10 n 20 where n is the dB offset If you place the value 1 413 for this example in K1 define the function as SPEC K1 9 21 Key Reference DEFINE Kx softkey When you change a function s definition the old definition is displayed in a small box in the center of the screen The new definition the one you are constructing with the operand and operator menus is displayed at the top of the screen
159. on procedure and set the analyzer s internal clock User Define lets you create and run HP Instrument BASIC programs if your analyzer is equipped with the HP Instrument BASIC option Plot Print controls selection and configuration of an external plotter or printer Local HP 1B provides HP IB options when the analyzer is under local front panel control Preset returns most of the analyzer settings to their default positions see The Preset Key later in this chapter 2 26 Front Panel Overview The Preset Key The Preset Key Preset Key Pressing Preset returns most of the analyzer settings to their default positions Before pressing Preset you may want to save the analyzer s settings particularly if your measurement setup was rather complex You can save an instrument setup state to disk by pressing Save Recall and using SAVE STATE If you simply want a hardcopy of the instrument setup state press Format Then press SETUP STATE to view a listing of the analyzer s current setup state Then press Plot Print and PLOT ALL or PRINT ALL MERSUREMENT Type FREQUENCY SHEEP RES BA NOISE SOURCE INPUT TRIGGER AVERAGE Swept Spectrum 109 Bea Hz 150 699 9809 Hz 75 259 988 Hz 149 989 880 Hz 269 88 mSec Value 17 ABA Hz Vid Filt OFF Bandwidth 18 189 Hz Status Impedance Start Stop Center Span Time Off 58 Ohms 18 d m 58 Ohm
160. ontains just one such softkey the key is active when you enter the menu If a menu contains two or more of these softkeys only one of them is active when you enter the menu Note The analyzer indicates that a numeric entry softkey is active by highlighting the cal whole softkey label The active numeric entry softkey is ready to accept a new value at any time You don t need to press it before entering a new value with the number keys or stepping the old value with the arrow keys When you start entering a new value with the number keys the softkey s entry box is displayed at the top of the screen The box remains on the screen until you either complete or abort the entry You complete an entry by pressing the ENTER softkey or a unit softkey You abort an entry by pressing CANCEL RETURN When you step the value of a numeric entry softkey with the arrow keys the entry box is displayed for a couple of seconds so you can see the new value You do need to press a numeric entry key even the active one if you want to change its value by turning the knob The knob is normally used to move the marker and can only be used for numeric entry if an entry box is displayed When you press a numeric entry key its entry box is displayed at the top of the screen for a couple of seconds If you start turning the knob while the box is still up the box remains up until you stop You can watch the value change as you turn the knob
161. orm the softkey menu Throughout this book softkeys are printed like this SOFTKEY Some softkeys toggle through different settings Toggle softkeys have a highlighted word in their label that changes with each press of the softkey Throughout this book toggle softkeys are depicted as they appear after you make the keypress For example toggle to FREQ CNTR ON OFF J means to press FREQ CNTR ON OFF until the word ON is highlighted Front Panel Overview Display Area Display Area Display Mini state The mini state is a small area that shows several of the analyzer s current settings including Range Resolution bandwidth swept spectrum measurements only Video bandwidth swept spectrum measurements only Sweep time swept spectrum measurements only High Accuracy or High Resolution position narrow band zoom measurements only Mini state 28 2 12 Front Panel Overview Display Area Marker Readout Range gbe 29 Dec 1989 13 34 Res BM 17 998 Hz Vew Off o Step Time 524 8 mSec R PENE gree Marker Readout Center 74 ak 728 7 Hz gt The marker readout provides the amplitude and frequency coordinates of the current marker position When the offset marker is on the marker readout indicates amplitude and frequency relative to the point where you zeroed the offset marker The marker s frequency value is only as accurate as the current display resolution for maximum
162. ou change from narrow band zoom to swept spectrum measurements But in this case it restores the span from the previous swept spectrum measurement 9 74 Key Reference NOISE LVL ON OFF softkey NOISE LVL ON OFF softkey Key Path Marker Fctn Press NOISE LVL ON OFF softkey to enable and disable the analyzer s noise level function You can use the noise level function to determine the noise spectral density normalized to a 1 Hz bandwidth at the main marker position The measured noise level is displayed as the marker readout s y axis value Note When offset marker is on the noise level readout is relative to the offset marker w position During swept spectrum measurements the analyzer sweeps to the marker position measures the noise level then completes the sweep Or if manual sweeping is selected the analyzer just measures noise at the manual frequency When a noise level measurement has been completed the marker readout s y axis value is highlighted Note The noise level function is not available for narrow band zoom measurements 4 The following conditions must be met before the analyzer can accurately measure noise level w The noise you are measuring must be random noise a The analyzer s resolution bandwidth RBW must be narrow enough to exclude any discrete signals such as tones from the noise measurement m The analyzer s RBW must be narrow enough to resolve a relatively flat portion
163. pace You can not change the size of the non volatile RAM disk All format options reformat the disk to the same size NORMLIZED SPECTRUN softkey Key Path Trace Data Press NORMLIZED SPECTRUM to display a normalized spectrum in the active trace To create a normalized spectrum the analyzer divides calibrated input data the data displayed when you press INPUT SPECTRUM by a reference trace The reference trace is stored in data register D8 when you press SAVE NORM REFERENCE 9 77 Key Reference NUMBER AVERAGES softkey NUMBER AVERAGES softkey Key Path Avg Pk Hid The NUMBER AVERAGES softkey uses a single value N in the following description to specify both a weighting factor and a count for video averaging During video averaging new and old measurement data is combined to create an average value for each point on the trace The analyzer uses this formula to combine the data CUN new N 1 N old The count is important when you use HP Instrument BASIC s keystroke recording feature Ifthe recorded keystroke sequence includes Meas Restart subsequent keystrokes are held off until N measurements are completed Note The analyzer does not stop measuring after N measurements If you want the analyzer to stop measuring select manual arming 9 78 Key Reference Numeric entry softkeys Numeric entry softkeys Some softkeys let you change numeric parameters If a menu c
164. pan is selected They are Hz at all other times Y axis units are dBm when you are displaying an input spectrum Y axis values are determined by the following formula 10 log Magnitude 2 001 Z When the analyzer s input impedance is set to 50 ohms or 75 ohms Z equals the input impedance When the analyzer s input impedance is set to 1 megohm Z equals the value you have specified in 1 MEG REF IMPEDANCE 9 62 Key Reference LOW DIST ON OFF softkey LOW DIST ON OFF softkey Key Path Meas Type Press LOW DIST ON OFF to enable and disable the analyzer s low distortion mode Spectrum analyzers introduce low level distortion products of the signals they are measuring The relative level of these products varies but all analyzers introduce them The distortion contribution of an analyzer becomes important when you are measuring spectral components that are near the analyzer s distortion specification Low distortion mode reduces the distortion contribution of the HP 3588A s analog input circuitry If you are measuring components that are within 10 dB of the published distortion specification this mode may improve your measurement results Note Continuous autoranging is not possible in low distortion mode but you can still use wj the SINGLE AUTORANGE softkey Low distortion comes at a price the analyzer s noise floor increases However you can offset this increase by
165. put circuitry The following table shows the maximum signal level for each of the analyzer s five ranges 20 dBm 21 76 dBm 2 24 Vrms 3 35 Vrms 10 dBm 11 76 dBm 707 mVrms 1 06 Vrms 0 dBm 1 76 dBm 0 dBm 223 mVrms 335 mVrms re mVrms 13 dBV 10 dBm 8 23 dBm 70 7 mVrms 106 mVrms 20 dBm 18 23 dBm 22 4 mVrms 33 5 mVrms Referenced to 50Q Note Only the 0 dBm referenced to 50 ohms range is available if you select the 1 MQ input impedance The easiest way to change the range is to use the arrow keys If you enter a range with the number keys the value is automatically changed to the next larger available range 9 101 Key Reference RANGE softkey Note If reference level tracking is turned on the reference level changes when you eel change the range If you choose to set the range manually you should watch for the over range RNG and overload OVLD indicators at the bottom of the screen They are displayed when the input circuitry is being overdriven as a reminder that you should either change to a less sensitive range or reduce the input signal level The over range indicator is sensitive to all signals between 0 and 150 MHz including those that are outside the current span As a result you may see RNG displayed even when a trace contains no over range components The overload indicator is only sensitive to signals within the current
166. quency as the new center frequency Setting the center frequency accurately makes it easier to locate components when you select increasingly smaller frequency spans particularly when switching to narrow band zoom measurements Alternatively you can use SIGNL TRK ON OFF to keep the largest component at the center when using smaller spans See Signal Tracking in chapter 7 Measurement Enhancements Center frequency is also important when making measurements using Zero Span and Manual Sweep To learn about Zero Span see chapter 4 Swept Spectrum Measurements To learn about Manual Sweep see chapter 8 Manual Sweep Offset to span The offset marker to span feature lets you quickly display a frequency span of interest without specifying start or stop frequencies Simply zero the offset marker at the point where you want the new span to start and place the main marker on the desired stop point After pressing OFS MKR gt SPAN the analyzer creates a new span based on the position of the offset and main markers 6 4 Marker Functions Peak Track Peak Track When peak tracking is on the analyzer automatically moves the main marker to the peak spectral line every time a new spectrum is displayed To turn on peak tracking toggle to PEAK TRK ON OFF Peak track is available for both Swept Spectrum and Narrow Band Zoom measurements You can also use peak tracking for manual sweep In manual sw
167. r is ado A NA RARAS NA EA AE 3 1 Porti A A RARAS 3 3 External Reference Input EXT REFIN 9c 6 6 4 6 906 ao eee A tc 3 4 Oven Reference Output OVEN REF OUT o o oooooooooono ono 3 5 Reference Output REF OUT 6 icin Sow A tt eet eee eh ees 3 6 External Trigger Input EXT TRIG oie a ee Sa di aaa iy ang Sat 3 7 Trigger Output ORIG OUT ms erea aca A SG AR Ree Be RW Bak kh ed 3 8 Chapter 4 Swept Spectrum Measurements O A NO 4 1 VETS WEED a AAA AS AA A E id ts da 4 3 Resolution Bandwidth AR aaa A ko Sa ane 4 3 Video Filtering and Video Bandwidth lt 4 0480 6566S ss 45 ewe cee nee ee wees 4 4 Bandwidth Coupling a ARS A A 4 5 a A was Gib sta elena BPE AEM ADO eM Bie ak ae pe A Beene 4 5 Changing Bandwidth Coupling e voca ana Nw a ale a s ea eK OO 4 5 Turning Off Bandwidth Coupling 2 2 ee te eee ee 4 9 Sweep TIME SRA et ee OSS Mark in Sas Bre Ota e 4 10 Manyal Sweep A hg Ae ata ete RR hte MA EE OG Awe ach ee A ee 4 14 LLO SPAN EA AENA rd tas Syl Sore a 4 15 OVErVIEW A BO wt 2 ek ani Aaa eve de erty ed ke te Arete bone the dete 4 15 Special Considerations for Zero Span 6 ee ee eee ee ee 4 16 Chapter 5 Narrew Band Zoom Measurements es EA eked ee A SS BAG See Bl edhe ee ek eS eae a Bie hota eee aed 5 1 Setting the Center Frequency oa a e a ew aa dl 5 2 High Accuracy Zoom versus High Resolution Zoom o o ooo 5 2 Chapter 6 Marker Functions The Main Marker The Offset
168. r specific information about a particular hardkey or softkey see chapter 9 Key Reference Alternatively use the analyzer s Help key to learn about a hardkey or softkey Input weed Sed ed a e ml pans er as pan em ee E OE MeT tl iJ e omar a cmd cen I INPUT The analyzer has one input connector The input is a de coupled single ended unbalanced input However the input is dc coupled only as far as the input attenuators from a measurement perspective the analyzer is ac coupled To specify the input impedance press Input Then use the appropriate softkey to select the 502 75 or 1 MQ input impedance 2 1 Front Panel Overview Input The HP 3588A Spectrum analyzer has five input ranges The following table shows the maximum allowable input levels for each range Maximum input levels for each range 5092 7159 20 dBm 21 76 dBm 2 24 Vrms 3 35 Vrms 10 dBm 11 76 dBm 707 mVrms 1 06 Vrms 0 dBm 1 76 dBm 0 dBm 223 mVrms 335 mVrms 223 mVrms 13 dBV 10 dBm 8283d8Bm 70 7 mVrms 106 mVrms 20 dBm 18 23 dBm 22 4 mVrms 33 5 mVrms referenced to 500 Maximum allowable de offsets Autoranging When autoranging is on the analyzer continuously monitors the amplitude of the input signals and if necessary automatically changes the input range If the input signal increases enough to exceed the current input range
169. ral density trace NBW is a calculated value that changes with the current measurement setup To learn more see Trace Math in chapter 7 Measurement Enhancements 6 9 Marker Functions Limit Testing Limit Testing Overview A limit test is a line or set of lines that you create to check the performance of a signal source or a device under test When limit testing is on the analyzer compares a current measurement or a stored trace to the limit you ve selected A limit appears as a single line upper or lower limit or two lines upper and lower limit If a trace exceeds the boundaries of these lines the limit test fails Limit testing is useful for go no go checking since a limit test quickly tells you if your device under test passes or fails a particular limit test You can build a limit line an upper limit a lower l mit or set of both upper and lower limits in several different ways By using the knob or numeric entry to arbitrarily construct a limit line By saving a trace recalling it as a limit and shifting this newly created limit up or down to form an upper or lower limit Via HP IB To learn how to build limits see chapter 6 Limit Testing in the HP 35884 Getting Started Guide Absolute and Relative Limits There are two ways you can use a limit as an absolute limit or as a relative limits Once you ve created a limit you can use it as an absolute limit or a relative limit depe
170. rameters the value Of USER STEP SIZE defines the following things u The smallest frequency change possible when you turn the knob slowly m The frequency change that results when you press an arrow key once Note The value you specify for USER STEP SIZE is only used if you toggle t STEP SIZE AUTO USER to USER UTILITIES softkey Key Path User Define The softkeys grouped under UTILITIES let you do the following things for your HP Instrument BASIC program a Allocate memory for the programs stack m Scratch delete the program and its variables e Renumber its lines Secure some or all of its lines 9 142 Key Reference VERTICAL DIV softkey VERTICAL DIV softkey Key Path Scale Press the VERTICAL DIV softkey when you want to compress or expand the active trace along its vertical axis To compress the trace increase the value of VERTICAL DWV J The vertical axis of a trace box is divided by equally spaced graticule lines or tick marks VERTICAL DIV lets you define the height of each division Note There are ten vertical divisions when the trace format is single or front back There are only five divisions when the trace format is upper lower A suffix menu lets you define the vertical scale in linear units Vrms or logarithmic units dB depending on the coordinate system being used You can select a coordinate system under the Trace Type hardkey VID FLTR ON OF
171. ransmission path length is 2 meters times the number of devices or 20 meters whichever is less Operating distances can be extended using an HP IB extender 3 1 Rear Panel Overview HP IB connector To learn more about controlling the analyzer over the HP IB see the HP 35884 HP IB Programing Reference Caution The analyzer contains metric threaded HP IB cable mounting studs as opposed to Y English threads Metric threaded HP IB cable lockscrews must be used to secure the cable to the analyzer Metric threaded fasteners are colored black while English threaded fasteners are colored silver Rear Panel Overview Port 1 Port 1 This connector is not active at this time 3 3 Rear Panel Overview External Reference Input EXT REF IN External Reference Input EXT REF IN External Reference input The analyzer has an internal 10 MHz frequency reference that can be locked to the optional temperature controlled 10 MHz reference or to an external frequency standard This allows the analyzer to make measurements with even greater frequency accuracy If your HP 3588A analyzer is equipped with an optional temperature controlled reference there will be an OVEN REF OUT connector on the rear panel There should be a BNC jumper in place between the EXT REF IN connector and the OVEN REF OUT connector If the jumper is not connected the analyzer s internal 10 MHz reference will not be locked to the temperature controlled refe
172. rate the analyzer from the front panel and it will display the command mnemonics you must send over the bus to achieve the same results Mnemonics are displayed in the lower left corner of the screen Note The lower left corner of the screen is also used for measurement status messages things like Averaging and Waiting for Arm When echoing is on these messages are not displayed Not every keystroke generates an HP IB command For example you must press Freq CENTER 5 0 MHz before the command FREQ CENT 50 MHz is echoed to the screen 9 30 Key Reference EDIT softkey EDIT softkey Key Path User Define Press EDIT to view or edit your HP Instrument BASIC program The analyzer enters HP Instrument BASIC edit mode and remains in this mode until you press END EDIT Most hardkeys are redefined as alpha characters when the analyzer is in HP Instrument BASIC edit mode Engraved letters adjacent to the lower right corners of these keys tell you which characters they will insert in your program The Help J Preset number decimal point and Back Space hardkeys are not redefined but the hardkey is It inserts a minus or dash in your program rather than toggling a number between positive and negative values Use the knob to position the text cursor in your program When you turn the knob clockwise the cursor moves to the right of a line and then down to the nex
173. rce 20dB A Out Srce 20dB B Out Srce DAC Atten 0 dB These parameters are not affected by Preset but are returned to the following values at power up Function registers cleared Constant registers cleared Data registers cleared Limit registers cleared Memory Size 8192 bytes Scratch option Scratch Start Line renumber 10 Increment renumber 10 Start Line secure 1 End Line secure 32766 These parameters are retained in non volatile RAM so they are not affected by Preset or power up TN ad Local HP 1B hardkey Controller Capability Analyzer Address Plotter Address Printer Address 9 98 Key Reference PRINT ALL softkey PRINT ALL softkey Key Path Plot Print Press the PRINT ALL softkey to print everything on the analyzer s screen except for the softkey labels PRINT ALL prints any of the following things Traces a The instrument state The disk catalog s Output from an HP Instrument BASIC program PRINT ALL does not print HP Instrument BASIC programs or Help screens Press PRINT PROGRAM in the User Define menu to print a program Press 8 to print a displayed Help screen Print information is sent as a bit mapped graphic so your printer must accept raster dumps Mapping of screen pixels to printer pixels is one to one Note Printing is only possible if the SYSTEM CONTROLLR softkey is selected and if the me valu
174. rdkeys When it s no longer necessary to enter alpha characters the analyzer automatically returns these hardkeys to their normal functions 2 23 Front Panel Overview Measurement Keys Measurement Keys 1 Measurement Keys LLLLLLLLLL The Measurement keys let you control the analyzer s input configuration measurement range and measurement resolution Here s a brief summary of the Measurement keys and their significant functions m Meas Type switches between swept spectrum and narrow band zoom measurements m Freq determines the frequency range measured a Res BW adjusts the resolution bandwidth and video bandwidth m Meas Restart initiates a new measurement a Range Input sets the current input range and impedance Sweep adjusts the sweep time and controls the local oscillator during manually swept measurements m Trigger provides trigger choices and manual arming a Average Peak Hold lets you select exponentially averaged or peak hold measurements u Source controls the analyzer s source output 2 24 Front Panel Overview Display Keys Display Keys S Display Keys LLLLLLLLLL The Display keys let you control what appears on the analyzer s two traces Since only one trace is active at any given time only one trace is the target of any adjustments you make using the display keys Here s a brief summary of the Display keys and their significant functions
175. re recalled from the default disk unless you include a disk specifier in the filename prompt When you recall a set of math definitions you are prompted for a filename If the catalog is off the prompt contains a default filename MATH If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys 9 104 Key Reference RECALL MORE softkey RECALL MORE softkey Key Path Save Recall RECALL MORE just displays a menu Softkeys in the menu allow you to recall any of the following e A limit definition upper or lower a Aset of math definitions m An HP Instrument BASIC program RECALL PROGRAN softkey Key Path Save Recall gt RECALL MORE Use RECALL PROGRAM to load an HP Instrument BASIC program into the analyzer The program is recalled from the default disk unless you include a disk specifier in the filename prompt When you recall a program you are prompted for a filename If the catalog is off the prompt contains a default filename either PROG or the name of the last program you saved or recalled If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys RECALL STATE softkey Key Path Save Recall Use RECALL STATE to replace the current instrument state with a saved state The state is rec
176. reducing the value of RES BW for swept spectrum measurements or by selecting HI RES Z00M for narrow band zoom measurements Note Low distortion mode is not available if you have selected an input impedance of e 1 megohm 9 63 Key Reference MANUAL FREQ softkey MANUAL FREQ softkey Key Path Sweep Press MANUAL FREQ to change the analyzer s measurement frequency during manual sweeps An entry box is displayed so you can enter a new frequency The range of values for MANUAL FREQ is limited by the current values of START and STOP You can change the manual frequency in the usual ways but with the following enhancements and exceptions You can control the sensitivity of the knob and arrow keys with STEP SIZE AUTO USER and USER STEP SIZE w The automatic step size is 1 30 of the resolution bandwidth or the width of one display point whichever is smaller u You can set MANUAL FREQ to the marker s current x axis value with the Marker Value hardkey a The MANUAL FREQ entry box is displayed until you press a nonnumeric hardkey While the box is displayed the knob can only be used to change the manual frequency When you use the knob to sweep the manual frequency you can skip some display points if you turn the knob too fast If this happens just use the arrow keys or the number keys to avoid skipping points Note The value of MANUAL FREQ can change when you redefi
177. rence Alternatively you can connect an external frequency standard to the External Reference Input This signal must be a 1 MHz 2 MHz 5 MHz or 10 MHz sine or square wave and should be between 5 dBm and 10 dBm The impedance is nominally 509 but is not critical The REF status indicator at the lower right hand corner of the analyzer s screen is visible when there is a signal applied to the External Frequency Reference connector If the external reference become unstable or is not at the proper frequency the REF indicator disappears and an external reference unlock message appears on the analyzer s screen 3 4 Rear Panel Overview Oven Reference Output OVEN REF OUT Oven Reference Output OVEN REF OUT Oven Reference Output Your HP 3588A analyzer may be equipped with an optional 10 MHz crystal oven If your analyzer has this temperature controlled reference there will be an OVEN REF OUT connector on the rear panel There should be a BNC jumper in place between the EXT REF IN connector and the OVEN REF OUT connector If the jumper is not connected the analyzer s internal 10 MHz reference will not be locked to the temperature controlled reference Keep in mind that the temperature controlled reference requires approximately fifteen minutes to warm up In fact no signal at all appears at the oven output connector during this warm up period So if you ve just turned on the analyzer the analyzer s uses its
178. rence level unit When you are ready to anchor a segment endpoint at the position of the limit marker just press START SEGMENT or FINISH SEGMENT Multiply softkey See Operator Menu 9 73 Key Reference NARROW BAND ZOOM softkey NARROW BAND ZOOMI softkey Key Path Meas Type Press NARROW BAND ZOOM when you want to make measurements at spans below 40 kHz You can also make swept spectrum measurements at these narrow spans but comparable narrow band zoom measurements can be made in much less time During narrow band zoom measurements the analyzer fixes its local oscillator LO frequency The signal in the IF around the center frequency you specify is then sampled over time The resulting block of time domain data is then transformed to the frequency domain using the Fast Fourier Transform FFT Note You can control the frequency resolution of narrow band zoom measurements with e the Zoom Type softkeys The analyzer maintains the current center frequency when you change from swept spectrum to narrow band zoom measurements However it selects a new span from the 16 available in narrow band zoom according to the following rules w Ifthe current span is greater than or equal to 40 kHz you get a 40 kHz span a ifthe current span is less than 40 kHz you get the closest available span that is greater than or equal to the current span The analyzer also maintains the current center frequency when y
179. requency Setting the Center Frequency Narrow band zoom measurements are particularly useful when examining modulation or noise sidebands of a spectral component The easiest way to position a frequency span when using narrow band zoom is to specify the center frequency For example to place a 40 kHz span around a 10 MHz component you simply press Freq CENTER and enter 10 MHz To measure a series of equally spaced components a series of harmonics for example you can step the center frequency and examine each harmonic and its close in sidebands To do this you must first set the step size to the fundamental s frequency To learn how to use this technique see Modifying the Step Size in chapter 7 Measurement Enhancements High Accuracy Zoom versus High Resolution Zoom When making narrow band zoom measurements you can select a high accuracy zoom or a high resolution zoom The default selection is high accuracy zoom If you need to measure the absolute or relative amplitude of a spectral component with great accuracy for example when using a fixed sine stimulus use high accuracy zoom Simply press Res BW then select Hi ACCRCY ZOOM J If it s more important to measure a component s frequency use high resolution zoom Simply press Res BW then select HI RES ZOOM Generally high resolution zoom offers greater resolution than the high accuracy zoom However the shape factor of the filter
180. ressing RUN Controller Capability softkey group Key Path Local HP iB Use the softkeys in this group to specify whether the analyzer should be the system controller in your HP IB system The following general rules will help you decide which key to select Select SYSTEM CONTROLLR if you want to initiate plotting or printing from the analyzer s front panel m Select SYSTEM CONTROLLR if you want to control other HP IB devices with an HP Instrument BASIC program Select ADDRESSBL ONLY if you want to operate the analyzer via an external HP IB controller 9 16 Key Reference Copy Disk softkeys Copy Disk softkeys Key Path Disk Util COPY DISK just displays a menu The menu contains all the softkeys you need to copy the contents of one disk to another disk m SOURCE DISK prompts you for the disk specifier of the disk you want to copy w DESTIN DISK prompts you for the disk specifier of the disk that will receive the new copy w PERFORM DISK COPY copies the contents of the source disk to the destination disk Note Any files on the destination disk are overwritten lost when you press z PERFORM DISK COPY When a disk prompt is displayed it already contains the specifier for the default disk You can use the specifier in the prompt or modify it with the alpha entry keys Since you can not copy a disk onto itself for example INT to INT you must modify the specifier in one
181. rier frequency make sure you ve adjusted the resolution bandwidth setting wide enough to include the modulated signal Modulation frequencies greater than one half the current resolution bandwidth may not be visible these frequencies are attenuated more than 3 dB and therefore fall outside the passband of the resolution bandwidth filter Select appropriate trace type If you want to measure amplitude in dBm use the logarithmic magnitude trace type If you want to measure amplitude in volts use the linear magnitude trace type When viewing modulation waveforms use linear magnitude trace type the logarithmic magnitude scale distorts the shape of the displayed modulation trace Use manual trigger arming to freeze the zero span trace When viewing modulation waveforms in zero span you can use manual trigger arming to freeze the trace This makes it easier to examine the display since the analyzer does not make another measurement until you press ARM 4 16 Narrow Band Zoom Measurements There are two measurement types available with the HP 3588A Spectrum Analyzer swept spectrum measurements and narrow band zoom measurements This chapter explains the narrow band zoom measurement type and the measurements you can make with it Introduction If you ve used a swept tuned spectrum analyzer before you already know that measurements of small frequency spans are very time consuming Traditionally swept tuned analyzers have require
182. rker position When peak tracking is off the main marker only moves from its current x axis position when you do one of the following things Turn the knob with no entry box displayed m Press a marker search key m Enter a new x axis position using MARKER X ENTRY Note Peak tracking is not available during manual sweeps 9 87 Key Reference PERFORM DISK COPY softkey PERFORM DISK COPY softkey See Copy Disk softkeys PERFORM FILE COPY softkey See Copy File softkeys PERFORM FORMAT softkey Key Path Disk util gt FORMAT DISK Press PERFORM FORMAT when you want to format a disk After you identify the disk it is formatted using the current values of FORMAT OPTION and INTRLEAVE FACTOR Note The analyzer s internal disk drive can only format double sided flexible disks Y When you press PERFORM FORMAT you are prompted to enter the disk specifier for the disk you want to format The prompt already contains the specifier for the default disk but you can modify it with the alpha entry keys You can append a volume name to the disk specifier when you format a disk Just position the cursor after the colon and enter a name of six characters or less Hint Use a unique volume name for each flexible disk to help you keep track of your data The name will be displayed in the upper left corner of the catalog PERFORM RENUMBER softkey Key Path User Define gt
183. rnal disk 270k 63k 640k 0 ek 6k emk 788k 63k 63k 64k Note If you enter a format option greater than 5 the formatting process is aborted when 9 you press PERFORM FORMAT and ENTER You can change FORMAT OPTION in the usual ways but with the following conditions Any value you enter with the number keys is changed to the closest integer in the range 0 5 m When you turn the knob slowly or press an arrow key one time the format option changes by 1 9 39 Key Reference FREE RUN TRIGGER softkey FREE RUN TRIGGER softkey Key Path Trigger Press FREE RUN TRIGGER if you don t need to trigger your measurements with a special signal Free run or continuous triggering allows the analyzer to trigger itself as soon as it is armed Note If you want the analyzer to take data continuously you must select both free run triggering and automatic arming 9 40 Key Reference FREQ CNTR ON OFF softkey FREQ CNTR ON OFF softkey Key Path Marker Fetn Press FREQ CNTR ON OFF to enable and disable the analyzer s frequency counter You can use the frequency counter to more accurately determine the frequency of the largest signal at the main marker position The measured frequency is displayed as the marker readout s x axis value Note When offset marker is on the frequency readout is relative to the offset e marker position You may want to turn the cou
184. s Some index entries are just there to help guide you to the right topic These entries are marked CXREF q _x II O i Caution The Preset hardkey will preset the analyzer settings even when you are using Y Help Select Preset hardkey in the Help index if you just want information on that key EEOhn o ULUS Press 8 to print one page of a help topic The analyzer must be the system controller The printer must be turned on attached to the analyzer s HP IB connector and set to the address specified under the printer address softkey 9 49 Key Reference HP IB controllers HP IB controllers When you connect devices via the HP IB one device must coordinate activity on the bus The coordinating device is called the controller The HP 3588A can act as a controller Sometimes you may have more than one device on the bus that can function as a controller Only one of these devices can coordinate bus activity at any given time The device that is currently coordinating bus activity is called the active controller One device on the bus must be designated as the system controller The system controller can always take control of the bus even if it is not currently the active controller The HP 3588A is designated as the system controller if you press SYSTEM CONTROLLR The HP 3588A cannot function as the system controller when ADDRESSBL ONLY is selected but it can
185. s pressing ZERO SPAN J 9 129 Key Reference START LINE softkey Renumber START LINE softkey Renumber Key Path User Define gt UTILITIES gt RENUMBER Before you renumber an HP Instrument BASIC program press START LINE to specify the new line number for the first line An entry box is displayed so you can enter a new value Note Renumbering acts on the entire program START LINE is used for the first program line after renumbering It does not specify where renumbering should begin in the original program After you have specified the starting line number and the increment between line numbers press PERFORM RENUMBER to renumber your program START LINE softkey Secure Key Path User Define gt UTILITIES gt SECURE Before you secure an HP Instrument BASIC program protect it against viewing you must specify the range of lines you want to secure Press START LINE to specify the first line in the range An entry box is displayed so you can enter a new value After you have specified the first and last lines press PERFORM SECURE to secure those lines and all lines that fall between them When you edit or print a secured line you will see an asterisk rather than program statements after the line number START SEGMENT softkey Key Path Marker Fetn gt LIMIT TEST gt DEFINE UPPER LIM Or Marker Fetn gt LIMIT T
186. s saved to the default disk unless you include a disk specifier in the filename prompt Caution The volatile RAM disk is cleared each time you turn the analyzer off Copy Y important state files to another disk before power down or they will be lost The instrument state includes function and constant register contents It does not include traces limit lines or data register contents When you save a state you are prompted for a filename If the catalog is off the prompt contains a default filename STATE If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys Note When you enter a filename that already exists the original file is overwritten g without additional prompting 9 115 Key Reference SAVE TRACE softkeys SAVE TRACE softkeys Key Path Save Recal The softkeys grouped under SAVE TRACE let you save the active trace to one of the following places u INTO FILE lets you save to the default disk or to any disk if you include a disk specifier a INTO Dx lets you save into data register x centers ee eee Caution The volatile RAM disk and all data registers are cleared each time you turn the analyzer off Copy important trace files to another disk before power down or they will be lost When you save to a disk you are prompted for a filename If the catalog is off the prompt contains a
187. s used does affect the detection of very small signals if a much larger signal is present So for looking at close in sidebands you may find that you get better resolution using high accuracy zoom rather than high resolution zoom Marker Functions The Main Marker The analyzer s main marker lets you determine the absolute frequency and amplitude of a spectral component s you move the marker with the knob the marker readout tells you the frequency and the amplitude of the component at the current marker position There s also an offset marker When you turn on the offset marker the main marker indicates frequency and amplitude values relative to the offset marker position Marker Functions The Offset Marker The Offset Marker You can use the offset marker to find the amplitude and frequency of one frequency component relative to another for example the relationship between a fundamental frequency and its harmonic Zeroing the offset marker at one point provides the reference point for the main marker Until you rezero the offset marker at another point the zero position remains where you set it even if you turn the offset marker off and then back on again But the zero position will be lost if you press Preset or turn the analyzer off When you press ZERO OFFSET the analyzer uses the current main marker position both x axis and y axis values to anchor the offset marker However if you ve turned on the anal
188. s used to abandon the function definition you are creating in favor of the one that already exists Output Impedance softkey group Key Path Source This group of softkeys allows you to select the output impedance of the analyzer s source When you select 50 OHMS OUTPUT Z J the output impedance is set to 50 ohms The dBm calculations for source amplitude assume a 50 ohm output impedance When you select 75 OHMS OUTPUT 2 the output impedance is still set to 50 ohms but dBm calculations for source amplitude assume a 75 ohm output impedance i ee Note If 75 OHMS OUTPUT Z is selected the actual and requested source amplitude only match if you use the 25Q adapter barrel supplied with the analyzer Insert the adapter between the source connector and your test device lt EEKKRQoc ernie en When you select COUPLE TO INPUT Z the output impedance tracks changes in input impedance with one exception If you switch from the 50 or 75Q input impedance to the 1 megohm input impedance the output impedance retains its current setting 9 83 Key Reference OVERSWEEP ON OFF softkey OVERSWEEP ON OFF softkey Key Path Sweep Press OVERSWEEP ON OFF to enable and disable oversweeping Oversweeping allows the HP 3588A to make swept measurements up to four times faster than other swept tuned analyzers Note Oversweeping is not available for narrow band zoom measurements 4 The HP 3588A uses a digital resolu
189. s when CENTER 5 MHz SPAN 20 MHz When this happens any portion of a trace that falls outside the range is blanked not displayed When bandwidth coupling is on changes in span may cause changes in the following parameters w Resolution bandwidth a Video bandwidth a Sweep time The range of values for SPAN depends on the measurement type selected m When SWEPT SPECTRUM is selected the range is 10 Hz to 150 MHz You can also enter a span of 0 Hz which has the same effect as pressing the ZERO SPAN softkey Values between 0 and 10 Hz are rounded up to 10 Hz u When NARROW BAND ZOOM is selected SPAN is limited to 16 discrete values The values range from 1 22 Hz to 40 kHz and are derived from the following formula 40 000 2 n n has integer values ranging from 0 through 15 You can change SPAN s value in the usual ways but with the following enhancements and exceptions m When SWEPT SPECTRUM is selected You can control the sensitivity of the knob and arrow keys with STEP SIZE AUTO USER and USER STEP SIZE Steps in autostep mode are members of a 1 2 5 series a When NARROW BAND ZOOM is selected Any value you enter from the numeric keypad is rounded to the next largest available span When the offset marker is on You can set SPAN to the marker readout s current x axis value with the Marker Value hardkey Pressing the OFFST MKR gt SPAN softkey has a sim
190. s wide Note When you use the front back trace format the vertical dimension of the full height s box is slightly compressed to make room for the second trace s annotation Two half height trace boxes are used for the upper lower trace format The graticules for these boxes are only five divisions high but are still ten divisions wide When you switch from full height to half height trace boxes the readout of vertical units per division is halved Trace Data hardkey The softkeys grouped under the Trace Data hardkey allow you to do two things m Select the data to be displayed in the active trace box w Create a title for the active trace Note You can display a function or constant using the options under this hardkey y However you must define a function or constant using the options under the Math hardkey 9 138 Key Reference TRACE TITLE softkey TRACE TITLE softkey Key Path Trace Data You can use the TRACE TITLE softkey to create a title for the active trace The title can be up to 15 characters long _ The analyzer enters alpha entry mode when you press TRACE TITLE To exit this mode and keep the new trace title press ENTER To exit this mode and reject the new title while retaining the old one press CANCEL RETURN Hint The title you enter replaces the analyzer s default title To restore the default just enter a title with no characters Press TRACE TITLE C
191. sample time is the time the analyzer takes to characterize the manual frequency If you select a shorter sample time it s easier to use the knob to adjust the manual frequency However you should use longer sample times greater than 1 RBW when you re making averaged measurements with manual sweep this ensures independent samples for each measurement and provides more accurate noise averaging Measurements made with manual sweeping take longer to set up but can take much less time to measure than with automatic normal sweeping particularly with narrow resolution bandwidths Use manual sweep for example when you want to a Measure the amplitude of a specific frequency without waiting for the analyzer to sweep through unwanted frequencies x Jump from frequency to frequency without waiting for the analyzer to sweep through unwanted frequencies And if you use the offset marker you can quickly measure the relative amplitudes of these frequencies as well a Adjust the output amplitude of a signal generator a Adjust a filter or other network to pass or stop a particular frequency Manual Sweep Special Considerations tor Manual Sweep Special Considerations for Manual Sweep For successful manual sweep measurements keep in mind the following characteristics Narrow resolution bandwidth settings can make it difficult to locate a test signal If there are no other signals near your test signal use the maximum resolution b
192. se specifies whether alpha characters entered by pressing redefined hardkeys should be upper case A Z or lower case a z Aipha entry mode Some analyzer keys prompt you to enter a text string Once you have pressed such a key the analyzer enters alpha entry mode and remains there until you accept or abandon the string You accept the string by pressing ENTER You abandon the string by pressing CANCEL RETURN J Most hardkeys are redefined as alpha characters when the analyzer is in alpha entry mode Engraved letters adjacent to the lower right corners of these keys tell you which characters they will insert in a string The Help Preset number decimal point and Back Space hardkeys are not redefined but the hardkey is It inserts a minus or dash in the string rather than toggling a number between positive and negative values Hint Use the knob to change the position of the text cursor when you edit a string Additional characters and editing functions are made available via the alpha entry menu ALPHA PEN softkey Key Path Piot Print gt DEFINE PLOT gt DEFINE PLOT PENS Press ALPHA PEN to specify which plotter pen should be used for plotting the instrument state and the disk catalog When you plot a trace the alpha pen is used for the state information at the top of the screen and for any status or error information 9 3 Key Reference AMPLITUDE STEP softkey
193. so use the HP 1120A 500 MHz Active Probe although this probe is no longer manufactured poe pee eee pun ere ca pe pe pe E 3 A ARSS Pp O canon comence e cr PERA al Active Probe Power 2 6 Front Panel Overview Source Source ay a ee pia fen ps J wt J ow an JJJ JL a come veneno aed pa ano A anesan SOURCE When activated the source connector supplies a sinusoidal signal whose frequency follows tracks the analyzer s swept tuned or manually tuned frequency At any given time the source frequency is tuned to the same frequency as the center frequency of the analyzer s input receiver This feature is similar to the tracking generator output provided on older Hewlett Packard spectrum analyzers One type of measurement you can make using the analyzer s source is a swept frequency response measurements This is a good way to characterize the amplitude vs frequency response of filters amplifiers and other electronic devices Incidentally the 3588A Spectrum Analyzer performs scalar amplitude only network measurements To learn more about scalar network measurements see chapter 7 Measurement Enhancements You can select a 50 or 752 impedance for the analyzer s source If you select 758 you must connect a 258 adapter a series feedthrough barrel between the source connector and the input of your test device This provides the necessary 50 to 75
194. sometimes make shorter calibrated sweep times available by increasing or decreasing the span a bit 10 to 20 percent Key Reference PACK DISK softkey PACK DISK softkey Key Path Disk Util Press PACK DISK when you want to increase the amount of usable space on one of the disks When you press PACK DISK you are prompted to enter the disk specifier for the disk you want to pack The prompt already contains the specifier for the default disk but you can modify it with the alpha entry keys When you delete files from a LIF formatted disk you sometimes leave spaces that are too small to be used for new files PACK DISK recovers these unusable spaces by shifting the remaining files forward on the disk until the files are directly adjacent to each other As files are shifted forward the spaces between files are effectively shifted to a large block of usable space at the end of the disk The result of this shifting is more usable space on the disk PAGE EJCT ON OFF softkey Key Path Piot Print gt DEFINE PLOT Press PAGE EJCT ON OFF to enable and disable your plotter s page eject feature The state you select is used for all plotting operations initiated by the analyzer Note Check your plotter s documentation to be sure that it supports the requested a page eject state Left Parenthesis softkey See Operand Menu Right Parenthesis softkey See Operator Menu 9 85 Key
195. span Either indicator may be displayed briefly when the analyzer is autoranging 9 102 Key Reference Range input hardkey Range Input hardkey The Range Input hardkey displays a menu You use the softkeys in this menu primarily to adjust the sensitivity and impedance of the analyzer s input circuitry Note The menu also contains a softkey that allows you to reset the input s my protective relay RE SAVE PROGRAN softkey Key Path Save Recall gt SAVE MORE Use RE SAVE PROGRAM to save the changes you make while editing the current HP Instrument BASIC program You can not use SAVE PROGRAM for this purpose because it doesn t allow you to overwrite an existing program in this case the last saved version of the program you are editing Both softkeys save your program to the default disk unless you include a disk specifier in the filename prompt Caution The volatile RAM disk is cleared each time you turn the analyzer off Copy Y important programs to another disk before power down or they will be lost When you save a program you are prompted for a filename If the catalog is off the prompt contains a default filename either PROG or the name of the last saved program If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys 9 103 Key Reference RECALL LINE softkey RECALL LI
196. ss DATA REG D1 D8 to gain access to the DATA REG Dx softkeys These softkeys let you specify the contents of corresponding data registers as function operands DATA REG D1 D8 softkey Trace Data Key Path Trace Data Press DATA REG D1 D8 for access to the Dx softkeys Each px key displays the contents of one of the analyzer s eight data registers You can use options under the SAVE TRACE and RECALL TRACE softkeys to load any data register You can use SAVE NORM REFERENCE to load D8 Data Reg Dx softkeys Key Path Math gt DEFINE Fx gt DATA REG D1 D8 When you are defining a function press one of the DATA REG Dx softkeys to specify the contents of the corresponding data register as an operand The abbreviation Dx is added to the end of the definition See also Operand Menu 9 18 Key Reference Data registers Data registers The analyzer has eight data registers D1 through D8 Each register holds a complete trace one that you have saved from the current measurement or recalled from a disk The trace in a register can be displayed directly or it can be used as an operand in a function Caution The data registers are cleared each time you turn the analyzer off Copy important y traces to any disk except the volatile RAM disk before power down or they will be lost DATE MMDDYY softkey Key Path Spel Fetn Press DATE MMDDYY to displ
197. surement types For more information see the description for each softkey 9 42 Key Reference Frequency resolution of the display Frequency resolution of the display Each trace box is divided along its x axis into 401 evenly spaced points For frequency domain measurements these points determine the frequency resolution of the analyzer s display Display resolution is not the same as measurement resolution The measurement resolution is determined by the resolution bandwidth swept measurements or by the zoom type narrow band zoom measurements Each display point has a nominal value This is the value used for the marker s x axis readout unless the frequency counter is on The nominal value of the first point point 0 is the start frequency The nominal value of the last point point 400 is the stop frequency Each display point represents a band of frequencies not just its nominal frequency For swept measurements using the peak detector and for all narrow band zoom measurements the amplitude Of the largest signal in the band becomes the amplitude of the point The width of this band is related to the current frequency span point bandwidth span 400 For swept spectrum measurements a display point represents the frequencies between its nominal frequency and the nominal frequency of the display point to its right AAA frequency span APA start siop freq freq ay ear aiid Point 0 Point 1 Point 2 cooo Point 4
198. t disk To rename a file on one of the other disks you must enter that disk s specifier in both filename prompts A name is automatically entered into each filename prompt If the catalog is off each prompt contains the filename last entered If the catalog is on each prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys RENUMBER softkey Key Path User Define gt UTILITIES RENUMBER displays a menu You use the softkeys in the menu to do three things a Specify the first line number of a renumbered program m Specify the increment between renumbered lines a Renumber a program based on the specified first line number and increment 9 108 Key Reference Res BW hardkey Res BW hardkey The softkeys grouped under the Res BW hardkey are used primarily to control the analyzer s measurement resolution Five of the softkeys are only available for swept spectrum measurements RES BW lets you select one of 15 bandwidths for the analyzer s resolution filter Use smaller values to increase measurement resolution ms VID FLTR ON OFF lets you enable and disable the analyzer s video filter u VIDEO BW lets you select a bandwidth for the video filter Use smaller values to smooth the noise floor m BW COUPLE ON OFF lets you enable and disable bandwidth coupling When coupling is enabled the analyzer automatically adj
199. t line When you turn the knob counter clockwise the cursor moves to the left and then up lt xo_ o U Note If you change or insert a program line be sure to press ENTER before moving to another line with the knob otherwise the change will be lost EEOOOOc o Additional characters and editing function are made available via the HP Instrument BASIC edit menu and its submenus 9 31 Key Reference ENABLE RECORDING softkey ENABLE RECORDING softkey Key Path User Define Press ENABLE RECORDING to begin recording front panel keystrokes Keystroke recording allows you to create an HP Instrument BASIC program that mimics a series of keystrokes It works by converting your keystrokes to equivalent HP IB commands and then enclosing the commands in BASIC OUTPUT statements When you have finished recording keystrokes press User Define to disable recording You can view or edit this program by pressing EDIT You can execute the program by pressing RUN Hint Be sure to record a Meas Restart keystroke before you record a keystroke that requires good measurement data such as MARKER gt PEAK This ensures that the measurement will be complete before your program uses the data The OUTPUT statements created by keystroke recording are entered into the current program If the program buffer is empty the analyzer first creates an ASSIGN statement and an END statement OUTPUT statements are then
200. ted stack space is not appropriate for some programs Here are two examples w Programs that call subprograms recursively usually require more stack space a Programs that have many subprograms but don t nest them deeply when running usually require less stack space Acceptable values for memory size range from 1200 bytes to 3 megabytes in 2 byte increments Note If you encounter the message ERROR 2 Memory overflow while your program T is running you need to allocate more stack space Menu definition The term menu simply refers to softkey labels that are displayed concurrently For example when you press the Avg Pk Hid hardkey the softkey labels OFF VIDEO AVERAGE PEAK HOLD and NUMBER AVERAGES appear These labels are referred to collectively as the Avg Pk Hid menu Minus softkey See Operator Menu 9 70 Key Reference MKR gt CTR FREQ softkey MKR gt CTR FREQ softkey Key Path Marker When you press MKR gt CTR FREQ the analyzer s center frequency is reset to current x axis value of the main marker the diamond shaped marker The marker is then moved to the new center frequency Here s how MKR gt CTR FREQ works in some special cases a The analyzer uses the measured frequency at the main marker if the frequency counter is on e The analyzer uses the main marker value even if the offset marker is on There is another way to change the c
201. termined by multiplying RBW by the following values 1 54 0 62 0 29 0 14 0 068 0 034 0 017 Note The analyzer always maintains the specified ratio between resolution bandwidth and ni video bandwidth even when bandwidth coupling is disabled 9 145 Key Reference VOLATILE RAM DISK softkey VOLATILE RAM DISK softkey Key Path Save Recall gt DEFAULT DISK or Disk Util gt DEFAULT DISK Press VOLATILE RAM DISK when you want to use some of the analyzer s volatile RAM as the default disk Caution The volatile RAM disk is cleared each time you turn the analyzer off Copy y important files to another disk before power down or they will be lost When you turn the analyzer on a 64 kilobyte volatile RAM disk is created If you need more storage space you must reformat the disk with a different format option File operations are much faster on the volatile RAM disk than on the internal disk This makes the volatile RAM disk very useful for HP Instrument BASIC programs Volume name Volume names allow you to uniquely identify each of your flexible disks They are displayed in the upper left corner of the disk catalog A volume name can be up to six characters long You assign it to a disk before formatting Just append the name to the disk specifier in the PERFORM FORMAT prompt ZERO OFFSET softkey Key Path Marker Press ZERO OFFSET to move the offset marker to the position
202. ters insert line mode it creates a blank line above the current line the one containing the text cursor and moves the cursor to that line When the editor exits insert line mode it deletes the current line and moves the text cursor to the next line Hint To save the contents of the current line press ENTER before you exit insert line mode When the editor is in insert line mode it adds a new line after the current line each time you press ENTER assuming the current line contains no syntax errors This continues until you exit insert line mode either by pressing INSERT LINE or by moving the text cursor to another line with the knob INSERT SPACE softkey Press this softkey to insert a space to the left of the text cursor during alpha entry or program editing INTERNAL DISK softkey Key Path Save Recall gt DEFAULT DISK or Disk Util gt DEFAULT DISK This softkey selects the analyzer s internal disk as the default disk The internal disk uses 3 5 inch flexible disks double sided double density for storage You must format each diskette before you use it Note The internal disk is optional If this softkey is ghosted the option is not installed Y INTO Dx softkey See SAVE TRACE softkeys 9 55 Key Reference INTO FILE softkey INTO FILE softkey See SAVE TRACE softkeys INTRLEAVE FACTOR softkey Key Path Disk Util gt FORMAT DISK Press
203. the prompt or modify it with the alpha entry keys Note When you enter a filename that already exists the original file is overwritten w without additional prompting 9 112 Key Reference SAVE MATH softkey SAVE MATH softkey Key Path Save Recall gt SAVE MORE Use SAVE MATH to save a complete set of math definitions all functions and constants to one of the disks The math file is saved to the default disk unless you include a disk specifier in the filename prompt Caution The volatile RAM disk is cleared each time you turn the analyzer off Copy y important math files to another disk before power down or they will be lost When you save a set of math definitions you are prompted for a filename If the catalog is off the prompt contains a default filename MATH If the catalog is on the prompt contains the name of the file currently highlighted You can use the name in the prompt or modify it with the alpha entry keys Note When you enter a filename that already exists the original file is overwritten y without additional prompting SAVE MORE softkey Key Path Save Recall SAVE MORE just displays a menu Softkeys in the menu allow you to save any of the following A limit definition upper or lower w Aset of math definitions An HP Instrument BASIC program 9 113 Key Reference SAVE NORM REFERENCE softkey SAVE NORM REFERENCE sofikey Key Path Trace
204. the start frequency a Swept spectrum and manual sweeping selected The analyzer begins sampling the amplitude of the manual frequency w Swept spectrum and zero span selected The analyzer begins sampling the amplitude of the center frequency a Narrow band zoom selected The analyzer begins gathering a new block of time domain data for transformation to the frequency domain Meas Restart has a special synchronizing function when you use keystroke recording to create an HP Instrument BASIC program When you replay the program keystrokes recorded after Meas Restart are not executed until the measurement is complete Meas Type hardkey The Meas Type hardkey displays a menu Use the softkeys in this menu to do the following things Change between swept spectrum and narrow band zoom measurements m Enable and disable the low distortion mode Enable and disable the peak detector 9 69 Key Reference MEMORY SIZE softkey MEMORY SIZE softkey Key Path User Define gt UTILITIES Press MEMORY SIZE to allocate stack space in bytes of volatile RAM for your program An entry box is displayed so you can specify a new value Stack space is the portion of memory used for temporary storage of program variables that are not stored in COM It provides the program s working space Stack space is set automatically when you recall a program or press AUTO MEMORY However the automatically genera
205. ticular frequency Adjusting the frequency of a test signal to match a frequency reference by adjusting the beat frequency to 0 Hz Note Zero span is available only when the analyzer is making swept spectrum w measurements Itis not available when making narrow band zoom measurements 4 15 Swept Spectrum Measurements Zero Span Special Considerations for Zero Span For successful measurements in zero span mode keep in mind the following characteristics Narrow resolution bandwidth settings can make it difficult to locate a test signal If there are no other signals near your test signal use the maximum resolution bandwidth 17 kHz Otherwise you may have difficulty finding your test signal particularly if you haven t set the center frequency to exactly the same frequency as your test signal Because the analyzer functions as a re fixed tuned receiver in zero span the analyzer s tuning is too sharp with a narrow resolution bandwidth to detect a test signal that isn t exactly at the specified center frequency Narrow resolution bandwidth settings provide selectivity to exclude closely spaced signals If you carefully set the center frequency you can use a narrow resolution bandwidth to exclude signals that are close to the frequency of your test signal For modulated signals use a resolution bandwidth setting wide enough to reveal the modulation If you re using zero span to view amplitude modulation of a car
206. tion bandwidth RBW filter rather than the analog filter used in more conventional swept tuned analyzers One property of digital filters makes oversweeping possible they settle more predictably than analog filters Since the settling of its digital RBW filter is predictable the HP 3588A can correct for sweep times that are too fast to allow complete settling The correction algorithm maintains the analyzer s amplitude and frequency accuracy in these overswept conditions Note Oversweeping increases the RBW filter s shape factor by about 30 percent y The oversweep correction algorithm makes an important assumption about the signals being analyzed it assumes that they are not changing in frequency during the sweep This assumption is invalid when you are using the analyzer s tracking source so oversweeping is automatically disabled when the source is on When video filtering is disabled the analyzer provides calibrated measurement results for sweep rates at or below the following limits given in Hz s u Oversweep on RBW 2 2 u Oversweep off RBW 2 2 Where RBW is the resolution bandwidth in Hz You can not always select a sweep time that allows you to achieve the maximum calibrated sweep rate Quantization effects produced by the analyzer s digital IF filter and local oscillator LO can limit the availability of calibrated sweep times These effects are most noticeable at narrow spans Hint You can
207. to sweep through an entire span a considerable advantage when using both a narrow resolution bandwidth and a narrow video bandwidth Manual sweep is particularly useful when making automated measurements Using manual sweep may reduce measurement time if you simply want to check the amplitude of several discrete frequencies that s because it s faster to transfer amplitude data for a few frequencies over the HP IB rather than sending data for the entire 401 point display When using manual sweep the analyzer is in effect a fixed tuned receiver You can change the tuned frequency with the knob or by entering a discrete frequency with the numeric entry keypad You can also step through a series of discrete frequencies by setting the step size accordingly Manual Sweep Using Manual Sweep Using Manual Sweep In manual sweep the analyzer s local oscillator remains at a single frequency in other words the analyzer acts as a fixed tuned receiver To tune to a desired frequency simply press MANUAL FREQ then enter an appropriate frequency with the knob or the numeric entry keypad Generally you should use the numeric keypad to select an approximate manual frequency then use the knob to search for a peak near the target frequency In effect you re using the knob to fine tune the local oscillator You can change the sample time by pressing SAMPLE TIME and using the knob or numeric entry keypad to specify a new value The
208. top automatically after a certain number of averages Video averaging does not lower the actual noise level However it does smooth the noise floor and in some cases can reveal low level components that would be obscured by the more uneven noise floor of an unaveraged measurement Averaging in the HP 3588A is an exponential average This means the number of averages you select determines the weighting of old data versus new data not simply the total number of averages calculated As you increase the number of averages new data is weighted less Exponential averaging is particularly useful for tracking data that changes over time To calculate the average the analyzer uses this formula next value new value Aka current value where N is a weighting factor the number of averages you ve specified Special Considerations With exponential averaging it s important to set the number of averages carefully If there are too few averages in the measurement the averaging will not smooth out variances But if there are too many averages the analyzer may not track subtle changes occurring within the data For example if you set N to 100 the new sweep data is weighted by 1 100 and the current data by 99 100 You can see that for this example each successive sweep does not change the trace very much If you change the input signal the displayed trace will show these changes very slowly Now consider another example sett
209. tting 9 93 Key Reference Plot Print hardkey Plot Print hardkey The softkeys grouped under the Plot Print hardkey are used to control the plotting and printing of screen contents Note The system controlir softkey must be selected before plotting or printing Also 9 PLOTTER ADDRESS and PRINTER ADDRESS must be correct Five softkeys in this menu allow you to plot selected portions of the analyzer s screen a PLOTALL m PLOTTRACE m PLOT MARKER m PLOT OFFST MKR x PLOT GRATICULE There are three additional softkeys m DEFINE PLOT provides access to submenus that allow you to define plot parameters m PRINT ALL prints everything on the screen except the softkey labels a ABORT PLOT PRINT lets you stop the current plot or print before it is completed Plots are scaled according to the established limits on the plotter The analyzer can t redefine these limits you must change them on the plotter Print information is sent as a bit mapped graphic so your printer must have raster dump capabilities Mapping of screen pixels to printer pixels is one to one The softkeys grouped under PloPrint allow you to plot or print the following things Traces s The instrument state a The disk catalog Output from an HP Instrument BASIC program However these softkeys do not allow you to plot or print HP Instrument BASIC programs or Help screens A program is printe
210. u need assistance and you don t have the analyzer s Getting Started Guide or Operating Manual near at hand The Help key is also a good way to learn about the analyzer or to refresh your memory if you don t use it often The help facility also has an index that lets you request information by key name or by topic The Getting Started Guide As we mentioned earlier the Getting Started Guide contains sample measurement tasks necessary for you to get comfortable quickly with the HP 3588A Spectrum Analyzer Each sample task demonstrates several commonly encountered spectrum analyzer measurements At the same time each task gradually introduces additional analyzer features By the time you finish the sample tasks you ll have a good understanding of the analyzer s most often used controls and features The Getting Started Guide also includes essential background information for people who haven t used a spectrum analyzer before You should read the Getting Started Guide before reading any other documentation for the HP 3588A Spectrum Analyzer Other Information For additional information about the HP 3588A Spectrum Analyzer use the following e For specifications installation instructions and performance tests see the HP 35884 Performance Test Guide s For service information see the HP 35884 Service Manual z To help you operate the analyzer remotely via HP IB see the HP 35884 HP IB Programming Reference a To learn more a
211. u ve selected automatic arming subsequent trigger signals are ignored while the measurement is in progress If you ve selected manual arming the analyzer ignores trigger signals until you press the ARM softkey or send this command via HP IB Rear Panel Overview Trigger Output TRIG OUT q AAA r q lt o_K_ QA A A Trigger Output TRIG OUT Trigger Output TRE Gut Tit REF OUY EXT TAG TH ee Tha 00000000000000 When the analyzer begins a measurement the TTL level signal on this connector goes low This provides a convenient signal to synchronize an external device Swept Spectrum Measurements There are two measurement types available with the HP 35884 Spectrum Analyzer swept spectrum measurements and narrow band zoom measurements This chapter explains the swept spectrum measurement type and the measurements you can make with it Swept Spectrum Overview When you select the swept spectrum measurement type the HP 35884 Spectrum Analyzer functions as a traditional triple conversion swept tuned spectrum analyzer The specified frequency range extends from 10 Hz to 150 MHz though you can measure frequencies less than 10 Hz However the analyzer s performance below 10 Hz is not specified If you ve used a swept tuned spectrum analyzer already you should have no trouble making measurements with the HP 3588A And even if you haven t used a spectrum analyzer before you ll find the HP 3588A quite easy to lear
212. ules One softkey DEFAULT PENS returns the other softkeys in this menu to their preset values 9 23 Key Reference DEFINE PLOT softkey DEFINE PLOT softkey Key Path Piot Print The DEFINE PLOT hardkey displays a menu You use the softkeys in this menu to do the following things m Specify plotter pens for various items on the analyzer s screen ws Specify a line type for trace A and trace B a Specify a plotting speed a Enable and disable your plotter s page eject feature A box is displayed in the center of the screen while you are defining plot parameters The box contains the currently specified pen numbers and line types Note Check your plotter s documentation to be sure that it supports the plot parameters y you request DEFINE UPPER LIM softkey Key Path Marker Fetn gt LIMIT TEST DEFINE UPPER LIM displays a menu The softkeys in the menu allow you to define or alter the upper limit for the active trace You define the upper limit as a series of line segments Here s how you use the softkeys in this menu to define the segments m MOVE MKR HORIZNTAL This lets you define the frequency value of a segment endpoint m MOVE MKR VERTICAL This lets you define the amplitude value of a segment endpoint START SEGMENT Press this softkey after you have defined the starting point of a segment a FINISH SEGMENT Press this softkey after you have defined the ending p
213. urements If you want the u analyzer to stop measuring select manual arming Averaging is tightly coupled to the following measurement parameters If you change one the average count is reset to 0 and the input spectrum is reset to the results of the next measurement a Measurement type swept or narrow band zoom Low distortion state Oversweep state m Frequency band center span start or stop Resolution bandwidth Video filter state Video bandwidth if video filter is on Zoom type high accuracy or high resolution Sweep state Manual frequency if sweep state is manual Input range Input impedance 1 MQ reference impedance if 1 MQ impedance is selected 9 144 Key Reference VIDEO BW softkey VIDEO BW softkey Key Path Res BW Press VIDEO BW to adjust the bandwidth of the analyzer s video filter When you decrease the bandwidth of the video filter the noise variance of swept spectrum measurements is reduced so you can see signals close to the noise floor Smaller video bandwidths require longer sweep times for a given span and resolution bandwidth If bandwidth coupling is on the sweep time is adjusted automatically when you change the video bandwidth If you use the number keys to change the value of VIDEO BW the value you enter is rounded up to the next largest video bandwidth Seven video bandwidths are available for each resolution bandwidth RBW setting They are de
214. urn off autoranging the analyzer will try to adjust its input range as the output of the test device changes and consequently will be unable to complete a measurement m Specify input range Press Range Input and then RANGE Then use the knob or numeric keypad to specify an input range appropriate for your test device a Specify source amplitude Press Source and toggle to SOURCE ON OFF to turn on the source Then press SOURCE AMPLITUDE and use the knob or numeric keypad to specify an appropriate level Select an output level appropriate for your test device if your device has gain set the source amplitude an appropriate level below the top of the input range to avoid overloading the input Turn off the peak detector Press Meas Type and toggle to PEAK DET ON OFF This turns off the analyzer s peak detector The peak detector while necessary for most measurements should not be used for most scalar network measurements Otherwise a slight frequency skew will occur To learn more about the peak detector see the sidebar on peak detection in chapter 4 Swept Spectrum Measurements Normalization For maximum accuracy in a scalar network measurement you can subtract any anomalies introduced by the test fixture Normalization also cancels out minor amplitude flatness errors in the analyzer s source Normalization is necessary only when you want to measure insertion loss and amplitude flatness of a test
215. usts res BW video BW and sweep time when you change the span BW COUPLE PRESET lets you optimize res BW video BW and sweep time for the current span Two of the softkeys are only available for narrow band zoom measurements w HI ACCRCY ZOOM w HIRES ZOOM These softkeys let you select one of two resolution values for narrow band zoom measurements HI ACCRCY ZOOM is the best choice for most measurements 9 109 Key Reference RES BW softkey RES BW softkey Key Path Res BW Press RES BW to change the bandwidth of the analyzer s resolution filter the final intermediate frequency IF filter The bandwidth of this filter controls the frequency resolution of swept spectrum measurements The analyzer can just resolve two signals of equal amplitude when their frequencies differ by the current resolution bandwidth RBW To see these signals on the display however you must select a span that separates the signals by at least one display point Note When bandwidth coupling is on the analyzer automatically adjusts the RBW as you t change the span You can lower the noise floor of a trace by narrowing the RBW This occurs because there is less noise energy within the bandwidth of a narrower filter However smaller RBWs require longer sweep times RESET softkey Key Path User Define gt DEBUG Press RESET to reset your HP Instrument BASIC program When you reset a program
216. ve trace Pressing Active Trace lets you designate alternately Trace A or Trace B as the active trace The Marker and Marker Fctn hardkeys are also tied to the active trace Although the markers for both Trace A and Trace B are always coupled if you have both Trace A and Trace B displayed you will see both markers moving together other marker functions are dedicated to the active trace For example if you press Marker and PEAK SEARCH the marker will move to the peak on the active trace only 2 15 Front Panel Overview Display Area Pop up Message Area Range dBm 29 Dec 1989 13 34 Res Ba 17 888 Hz VEW OFF Sup Time 24 8 mSec A SRE Mer 73 526 a89 Hz 49 Bm Pop up Message Area 74 282 728 7 2 Span 75 663 957 3 Hz Center When necessary the analyzer displays a pop up message window at the center of the screen Some examples of these messages are Autorange in progress Calibration in progress User error Hardware errors Y axis Notation The y axis notation includes the Trace Type Log Magnitude or Linear Magnitude and the top and bottom values amplitude values for the current y axis scale Range Y dBm 29 Der 1989 13 34 Res BW 17 BBB Hz VBW OFF Sug Time 524 8 mSee A EET OS OS EIA O O AE ib the Mir 73 526 989 Hz 1 48 bm REES AP quai A See AN O teiinin Y axis Notation srorregevivesase srersamesersere Ae ereageneerases PPPrer
217. view the contents of a limit register do the following 1 Press Active Trace if necessary to activate the trace associated with the limit 2 Toggle LINES ON OFF to ON 3 Scale the trace with VERTICAL DIV and REFERENCE LEVEL to bring the limit into view Note The contents of limit registers are not affected by Preset but they are lost when g you turn the analyzer off 9 57 Key Reference Limit Test softkey Limit Test softkey Key Path Marker Fetn The LIMIT TEST softkey displays a menu The menu gives you access to all the softkeys you need to define limits also called limit lines and to test trace data against those limits A special submenu allows you to define limits interactively from the front panel Two softkeys in the Limit Test menu provide access to this submenu DEFINE UPPER LIMIT J a DEFINE LOWER LIMIT J Two limit type softkeys let you specify how the upper and lower limits should respond to changes in the reference level setting m ABSOLUTE LIMIT m RELATIVE LIMIT The remaining softkeys in the Limit Test menu have the following functions a LINES ON OFF lets you enable and disable display of the limits m TEST EVAL ON OFF lets you enable and disable evaluation of trace data against the limits m FAIL BEEP ON OFF lets you specify whether the analyzer should beep when a limit test is failed Each limit is defined as a series of line segments and
218. ymbol the product will be marked with this A symbol when it is necessary for the user to refer to the instruction manual in order to protect against damage to the instrument Indicates dangerous voltage terminals fed from the interior by voltage h exceeding 1000 volts must be so marked Protective conductor terminal For protection against electrical shock L in case of a fault Used with field wiring terminals to indicate the OR terminal which must be connected to ground before operating equipment signal common as well as providing protection against electrical shock in case of a fault A terminal marked with this symbol must be connected to ground in the manner described in the installation operating manual and before operating the equipment Low noise or noiseless clean ground earth terminal Used for a L Frame or chassis terminal A connection to the frame chassis of the rh OR equipment which normally includes all exposed metal structures as Alternating current power line Direct current power line ms Alternating or direct current power line Warning The WARNING sign denotes a hazard It calls attention to a procedure i practice condition or the like which if not correctly performed or adhered gt to could result in injury or death to personnel Caution The CAUTION sign denotes a hazard It calls attention to an operating procedure practice condition or the like which if not correctly per
219. ys a menu that allows you to select a default disk Whenever you request operations that require disk access things like saving and renaming files the analyzer performs these operations on the default disk You can override the default disk selection by including a disk specifier in any filename or device prompt But if you select the disk you use most often as the default you won t need to enter specifiers You can select one of the following as the default disk although the optional disk may not be installed Non volatile RAM disk a Volatile RAM disk Internal disk optional Caution The volatile RAM disk is cleared each time you turn the analyzer off Copy y important files to another disk before power down or they will be lost 9 20 Key Reference DEFAULT PENS softkey DEFAULT PENS softkey Key Path Plot Print gt DEFINE PLOT gt DEFINE PLOT PENS Press DEFAULT PENS to return plotter pen assignments to the following preset values TRACE A PEN 2 TRACE B PEN 3 MARKER A PEN 5 MARKER B PEN 6 ALPHA PEN 4 GRATICULE PEN 1 DEFINE Fx softkey Key Path math The analyzer has five function registers F1 through F5 Each register holds a trace math function that you define To change the definition of a particular function or to display its current definition press the corresponding DEFINE Fx softkey Note The trace resulting fr
220. yzer s frequency counter the offset marker will be zeroed at the counted frequency And if you ve turned on the noise level marker the offset marker will be zeroed at the noise level reading The analyzer also keeps the zero point even if this point is no longer within the current frequency span For example you can zero the offset marker at 10 MHz and then change to a span that starts at 50 MHz and stops at 70 MHz and the marker readout will still provide the offset from 10 MHz The ability to keep the zero point when the zero point is no longer within the current span is very useful This lets you step through several narrow spans to find low level harmonics after initially zeroing on the fundamental To learn more about this see Locating signals quickly by stepping CENTER FREQUENCY in chapter 7 Measurement Enhancements Marker Readout The marker readout provides the amplitude and frequency values for the current marker position When the offset marker is on the marker readout indicates amplitude and frequency relative to the point where you zeroed the offset marker For zero span measurements the marker readout shows time not frequency To turn off the marker and the marker readout toggle to MARKER ON ON If you print or plot when the marker is off the marker and marker readout will not be included on the printout or plot The marker s frequency value is only as accurate as the current display resolutio
221. zard To clean dampen a soft lint free cloth and carefully wipe the screen Use only a mild detergent mixed with water 2 19 Front Panel Overview Marker Keys and Knob Marker Keys and Knob Marker Keys The Marker Keys The marker keys call up menus that lets you control the location and movement of the on screen marker These controls affect only the markers for the currently active trace The Knob The knob is an RPG rotary pulse generator that controls two things movement of the on screen marker and continuous entry of numeric values Usually the knob simply moves the marker Turn the knob to the right and the marker moves to the right Turn to the left and the marker moves left The faster you turn the knob the faster the marker moves If you have both Trace A and Trace B displayed you will see both markers moving together l After pressing a softkey that requires a numeric entry the knob becomes dedicated to numeric entry Turn the knob to the right and the analyzer steps through larger numeric entries Turn to the left and the analyzer steps through increasingly smaller entries Although the analyzer uses a default step size to control the sensitivity of the knob that is the interval between each numeric entry as you turn the knob you can select your own step size Press Freq toggle to STEP SIZE AUTO USER and press USER STEP SIZE Then use the numeric keypad to enter your own step size
222. zoom type softkeys control resolution for narrow band zoom measurements You can change the setting of an inactive softkey but the analyzer doesn t use the new setting until the key becomes active For example you can change RES BW while NARROW BAND ZOOM is selected but the analyzer doesn t use the new setting until you select SWEPT SPECTRUM The analyzer uses a ghosted font to indicate that a softkey is inactive INCREMENT softkey Key Path User Define gt UTILITIES gt RENUMBER Before you renumber an HP Instrument BASIC program press INCREMENT to specify the increment between the renumbered lines An entry box is displayed so you can enter a new value After you have specified the starting line number and the increment between line numbers press PERFORM RENUMBER to renumber your program 9 52 Key Reference input Impedance softkey group input Impedance softkey group Key Path Range Input This group of softkeys allows you select impedance of the analyzer s input circuitry When you select 50 OHMS the input connector is terminated with a 50 ohm resistance The dBm calculations for input range and trace amplitudes assume an input impedance of 50 ohms When you select 75 OHMS the input connector is still terminated with a 50 ohm resistance but dBm calculations assume an input impedance of 75 ohms Note When 75 OHM is selected you must use the 25 ohm adapter barr

HP Switch 3588A User's Manual

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