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Marconi 2018A/2019A AM/FM Synthesized Signal Generator

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1. Pulse Mod 409Y 409T Extended f m Pulse Mod 410E 410W Avionics Pulse Mod 411U 411D Extended fme Avionics _ Pulse Mod 412Y 412T 10 kHz Carrier Pulse Mod 413N 413P Extended fm 10 kHz Carrier Pulse Mod Confirmation of the variant s fitted can be obtained by comparing the number on the identification plate affixed to the rear of the instrument and the above list Chap l Jun 84 Page 3 H 52018 910P Vol 1l PERFORMANCE DATA 8 The performance specifications for 2018A and 2019A are in most respects identical therefore the following data applies to both instruments except where otherwise stated Other variants having different parameters are Specified only where a more limiting parameter applies Where a combination of options causes a parameter to be specified more than once then the more limiting parameter will apply Alternative parameter information that is specific to a variant is shown in bold type Characteristic Performance 2018A version 2019A version Carrier frequency 9 Range 80 kHz to 520 MHz usable 80 kHz to 1040 MHz usable down to 30 kHz down to 30 kHz AVIONICS VARIANTS Range 1 5 MHz to 520 MHz 1 5 MHz to 1040 MHz 10 kHz CARRIER VARIANTS Range 10 kHz to 520 MHz 10 kHz to 1040 MHz Resolution 10 Hz up to 520 MHz 10 Hz up to 520 MHz 20 Hz from 520 MHz to 1040 MHz RF output 10 Level accuracy 1 dB t dB from 80 kHz to 520 MHz 2 dB from 520 MHz to 1040 MHz AVIONIC VARIANTS Level accur
2. 3 MOD INPUT 100 kQ socket Accepts an input from an external modulation source When the HI and LO l e d s are extinguished the input voltage will be within the range 1 V 54 4 AUX FM INPUT socket Enables the use of additional modulation tones either with internal or external modulation source applied With 1 V YemeS applied the additional f m deviation produced is 104 of the f m display value 5 Function keys The nine orange keys each have an integral l e d to indicate the function currently selected hap 3 Bags 2 Jun 84 MARCONI INSTRUMENTS H 52018 910P Volal 80 kHz 1040 MHz signal generator 2019A CARRIER FREQUENCY MODULATION LEVEL LETOO Y WAF DALA DA Dad Dal i L 03 SECOND AF FUNCT OUTPUT L MOD CARRIER ON OFF ON OFF RF OUTPUT 500 REV PWR RESET RETURN A i REVERSE POWER q SOW MAX 4 4 Fig 1l Front panel controls 6 Numerical keypad Enters the required value for the function currently selected includes a minus sign and a decimal point 7 Units The four grey keys are used to terminate the numerical entry 8 Miscellaneous functions This right hand group of eight black keys is concerned with such operations as AF ON OFF INT EXT MOD ON OFF CARRIER ON OFF RETURN DECREMENT down INCREMENT up and TOTAL A 9 SECOND FUNCT This blue key with an integral l e d is used to provide
3. Less than 0 1 total harmonic distortion for a 1 kHz output frequency at an audio level of 5 V remes into 100 KQ lt 10 2 Internal or external frequency standard may be selected from the front panel Either 1 MHz or 10 MHz standard may be selected by second function control Annunciators show which is selected A rear panel BNC socket provides an output from the internal frequency standard at either 1 or 10 MHz when internal standard is selected This socket becomes the external standard input when external standard is selected High stability oven controlled 10 MHz crystal oscillator lt t0 1 pepem over temperature range of 0 to 409C Within 0 5 pepem of final frequency within 5 minutes from switch on at an ambient temperature of 20 C Chap 1 Page 1l Internal standard output External standard input Auxiliary inputs and outputs Characteristic 23 Modulation input External modulation input Auxiliary FM input Chap l Page 12 Deviation Accuracy Impedance H 52018 910P Vol 1 Performance Either 1 or 10 MHz nominally 3 V p p Square wave may be selected by second function control Source impedance 100 2 nominal Accepts 1 MHz or 10 MHz of at least 1 V YeMeSe Maximum recommended input level 2 5 V LeMeSe Input impedance is nominally 100 2 A front panel BNC socket accepts an external modulation input The input signal may be levelled by selecting the MOD ALC ON OFF ke
4. Reverse power protection store and recall second function operations second second second second Second Second second Second second Second Second Second second second Second Second Unlock Status GPIB address setting Manual latch setting SRQ mask setting RF level units setting RF level offsets Elapsed time display Read identity string Write user definable string Read user definable string 1 or 10 MHz standard setting Old new GPIB command set function 16 Recall STORE 10 at switch on function 18 Set data on GPIB Aux output pins functions 7 8 9 10 17 190 191 and 192 Second level operation function OQ function 1l function 2 function 3 function 4 function 5 function 6 function 9 function Ill function 12 function 13 function 14 function 15 Operation with 75 2 loads General purpose interface GPI8 functions Setting the GPIB address GPIB programming codes Listening function Talking function SFl QU Status string SF11 QU Identity string SF12 User string write facility SF13 QU User string read facility Service requests SRQ Error 84 numbers continued Chap 3 Page 1 H 52018 910P Vol 1 CONTENTS continued Para 68 SRQ mask 70 Reverse power protection 71 Clear switch on and return to local 72 Fast output facility GPIB only 73 GPIB connector contact assignments 74 GPIB au
5. 2018A resets to the default power up mode that is Maximum carrier frequency 2018A 520 MHz 2019A 1040 MHz No a M f me ome OY pulse modulation Minimum r f level 127 dBm or equivalent Modulation oscillator frequency 1 kHz Internal modulation selected Increment settings Carrier freq 1 kHz f m 1 kHz gt m l rad a m 14 r f level 1 dB or a f level 1 dB Before these conditions are set a checksum is calculated for the calibration data FM tracking and RF level and referred to a number held in the non volatile memory If this test of calibration validity fails the instrument responds by asserting SRQ The status byte will contain the number 6 to signal a calibration data fault in addition to the SRQ asserted bit In order to continue with the device clear and normal operation thereafter the instrument must be restarted by sending any valid instruction code e g CE This serves only as a reset and will not be interpreted in the normal waye Chap 3 Page 20 Jun 84 H 52018 910P Vole o 52 El Open collector drivers Re Tah A PNT D The GPIB drivers fitted to 2018A have open collector rather than tristate outputs Setting the GPIB address _ 53 The instrument s talk listen address is selected by means of the second function mode 2 Acceptable addresses 00 to 30 can be set by this means and the instrument s internal address register will be updated by reading the addre
6. connector SKAK is correctly aligned with GPIB module connector PLAK 3 Switch instrument on temporarily and check that the front panel displays data correctly If satisfactory switch off and continue with step 4 If display is corrupted however then re check the alignment of SKAK and PLAK as indicated in step 2 4 Using the four retaining screws provided secure the GPIB assembly to the rear panel where four pre positioned captive nuts are fitted The interface is now ready for GPIB operation Chap 2 Jun 84 Page 3 H 52018 910P Vol 1 LN OD I TD EP ET TS 8e 46883 follo Chap Page The instrument may be mounted in a standard 19 inch rack using the kit 506M available as an optional accessory Fitting instructions are as wsi 1 Remove both top and bottom outer covers detach and discard front and rear feet on bottom cover 2 Detach and discard side trim infills countersunk screws and screw CUupS 3 If it is desired to have the r f output and modulation input sockets on the rear panel complete steps 4 to l0 if rear panel connections are not required proceed to step ll 4 Remove the front panei assembly by slackening the two screws exposed in each side and lay face down protecting the l c d s 5 Disconnect the semi rigid coaxial plug PLAV situated at the rear of the top ref box and remove the four r f box securing screws one in each corner bracket raise the box into the servicing posit
7. Usable down to 1 Hz with reduced devia tion The instrument is suitable for testing receivers requiring signalling tones with a frequency modulation content down to 1 Hz settling time with FM on is up to approximately 5 seconds to be within 100 Hz of final frequency Chap 1 Page 7 Characteristic Stereo separation Distortion External modulation Phase modulation 18 Range Selection Display Frequency response Accuracy Chap 1 Page 8 H 52018 910P Vol l Performance Better than 50 dB at 1 kHz for carrier fre quencies from 88 MHz to 108 MHz Typical separation 56 53 dB 50 47 20 30 50 80 Hz 5 kHz 15 kHz Modulation frequency lt 3 total harmonic distortion at 1 kHz modulat ing frequency and a deviation of up to 04 of the maximum available at any carrier frequency lt 0 3 total harmonic distortion at 75 kHz de viation at carrier frequencies from 88 MHz to 108 MHz at 1 kHz internal modulating frequency or external source with a l c off With modulation a l c on the deviation is calibrated for input levels between 0 8 V and 1 2 V p d With modulation a l c off the deviation is calibrated for an input level of l V ped HI or LO l e d s are provided as an aid to maintain calibrated modulation in the a el c off mode Input impedance is nominally 100 KR Modulation index 0 to 10 radians for carrier frequencies below 2 03125 MHz O to a value in radians equal to
8. YooTg P TJTTdUTS V6107 V8I0Z Aux FM in Se RF BOX AA AB Mod in eee Frequency preg Std Standard infout 10 MHz 7 IMHzZ or AA 3 2 10MHz 1kHz LSD VGXO A o Loop Loop No f1 10 20 MHz f3 NU f2 2 8kHz AB5 FM Mod Osc and FM Control AAI Output Phase Detector Output f4 VRD AB4 AB1 FM Drive RF Oscillators AB3 FM Drive RF BOX AA AB NOte eee 2018A comprises basic instrument with board AC3 fitted 2019A includes board AC13 in lieu of AC3 this board provides AC3 functions and an additional fre quency doubler circuit The diagram does not include differences that would be created by the addition of variants 10 12 03125 MHz i 10MHz std 0 08 2 03125MHz 2 03125 32 5 MHz B F O System 520 1040 MHz 10 lt 0 08 32 5 MHz 12 031259MHz op l 2 03125 Filter Board l Amplitude ERRA E wasil My oe ae Modulator PEERS ER aot 0 eS J Step RF Output 2 03125 g Out put Attenuator AC5 520MHz AC3 or part 8 8 iu a Amplifier of ACI3 i i NK acs ATO i a U l l l Foe ere ne l Filter and l Frequency l or for 2019A instrument Doubler l i 0 08 1040 MHz 32 5 1040MHz l AC13 2019 only MODULATOR RF BOX 2 ACO ATO TPD4 amp 494A a in N O p lt O ke D e m m HJ
9. as a manually operated bench mounted instrument or as part of a fully automated test system Provision is also made for the use of either l MHz or 10 MHz external Standard frequency reference when this is preferred Output 3 Calibrated output levels from 127 dBm to 13 dBm 0 2 uV to 2 V emf in the C W em and m modes and up to 7 dBm 1 V e m f in the a m mode are provided A choice of nine output level calibration units can be obtained on the front panel The r f output level can be set to a resolution of Q 1 dB or better over the entire output voltage range and features a total cumulative accuracy of 1 dB up to 520 MHz 2 dB 520 MHz 1040 MHz Protection against the accidental application of up to 50 W of reverse power is provided by a fast responding reed relay Modulation ne Amplitude and frequency modulation can be carried out from either external or internal modulation sources The internal modulation source provides six fixed modulation frequencies suitable for most normal applications GPIB Marconi Instruments General Purpose Interface Bus in accordance with IEEE Standard 488 1978 and IEC Publication 625 1 and BS 6146 Pt l Ghape 1 Jun 84 H 52018 910P Vol 1l Front panel De The instrument settings are displayed by three liquid crystal displays that include annunciators to show the units of the displayed data All data is entered on a keyboard that has been designed to be simple and logical t
10. frequency standard selection and instrument stores are unaffected by the SDC and DCL commands 2 Switching on clears the 2018A to the same state as SDC or DCL unless Recall STORE 10 at switch on conditions apply Fast output facility GPIB only 72 This facility enables the instrument to be changed from one complete setting to another with the minimum possible transition time Two ASCII character pairs Hl and HO are used to set the facility on or off and a third GO Trigger output is used to implement the instruction as follows 1 Set Hl Trigger output mode is set to on causing all instrument outputs to remain unchanged when new settings are entered thus allowing the pre setting of several functions 2 Set GO Trigger output now instructs the instrument to change settings 3 Set HO Trigger output mode is set to off and instrument resumes normal operation GPIB connector contact assignments 73 The contact assignment of the GPIB cable connector and the device connector is as shown in Fig 8 below Chap 3 Page 26 Jun 84 H 52018 910P V ls 1 DIO 5 DIO 6 DIO 7 DIO 8 REN FORMS TWISTED PAIR WITH 6 FORMS TWISTED PAIR WITH 7 FORMS TWISTED PAIR WITH 8 FORMS TWISTED PAIR WITH 9 FORMS TWISTED PAIR WITH 10 FORMS TWISTED PAIR WITH 11 LOGIC EARTH TPB3350 Fig 8 GPIB connector contact assignments Chap 3 Jun 84 Page 27 67 87 e8eg deuy unr 78 21a 6 wWeisetq
11. indicate an SRQ request and the first five bits 0 to 4 indicate an error number The error number is also displayed in the carrier frequency window Errors 10 12 13 14 will result in the instrument not functioning Error 06 can be overridden with a restart command any function code or digit Similarly the RPP tripped Error Ol can be overridden with the reset instruction RS Chap 3 Page 24 Jun 84 H 520138 910P Vol 1 Error numbers 67 No Error condition Action taken Ol RPP TRIPPED Wait for reset instruction RS 02 INVALID FM TRACKING DATA Greater than 255 03 INVALID GPIB CHARACTER 04 OPTION NOT FITTED 05 GPIB BUS ERROR 06 CAL DATA CHECKSUM FAILURE Wait for restart instruction 07 any function code or digit 08 09 19 PROM CHECKSUM FAILURE Ll ATTEMPT TO OVERWRITE PROTECTED STORE 12 MAIN RAM CHECKSUM FAILURE IC18 13 STACK RAM CHECKSUM FAILURE 1IC12 14 BOTH RAMS CHECKSUM FAILURE 15 EXTERNAL FREQ STD ERROR 16 ILLEGAL STORE NUMBER 17 INVALID STORED DATA RECALL 18 EAROM WRITE FAILURE 19 INVALID FIRST CHARACTER OF PAIR 20 INVALID SECOND CHARACTER OF PAIR 21 INCOMPLETE CHARACTER PAIR 22 NO TALK FUNCTION SELECTED 23 NO SUCH FUNCTLON 24 EAROM READ FAILURE SRQ mask 68 The SRQ response to the errors listed above can be suppressed by setting a 3 page 8 bit mask via second function 4 The first 8 bits of page 1 refer reading from right to left to error numbers 1 to 8 page 2 error numbers 9 to 16 and page 3 error n
12. supply lead to a non soldered plug it is recommended that the tinned ends of the lead are first cut off owing to the danger of cold flow resulting in intermittent connections Chap 2 Page 2 Jun 84 H 52018 910P Vol 1 230 240V 0 5A T 115 120V 1A T 210 220V 0 5AT TPB 4495 Fig l Voltage ranges alternative switch and locking plate positions SAFETY TESTING 6 Where safety tests on the a c supply input circuit are required the following procedures can be applied These comply with BS 4743 and IEC Publication 348 Tests are to be carried out as follows and in the order given under ambient conditions to ensure that a c supply input circuit components and wiring including earthing are safe 1 Earth lead continuity test from any part of the metal frame to the bared end of the flexible lead for the earth pin of the uSer s a c Supply plug Preferably a heavy current about 25 A should be applied for not more than 5 seconds Test limit not greater than 0 5 Q 2 500 V d C insulation test from the a c supply circuit to earth Test limit not less than 2 MR GPIB INTERFACE 7 The GPIB interface is an optional accessory and can easily be fitted by the user as follows 1 Remove and discard the rectangular cover plate from the left hand Side of the rear panel 2 Withdraw the interconnecting lead from inside the instrument and connect this to the GPIB assembly taking care that the ribbon cable
13. the GPIB for particular conditions 24 possible error conditions are listed in the GPIB functions paragraphs although provision has been made for 30 At switch on all error numbers previously masked are automatically reset to the unmasked state i e 0 and displayed as a 6 bit binary number in the frequency display To give access to error numbers 1 to 30 inclusive requires five pages At switch on page 1 is automatically selected and error numbers 1 6 are represented from right to left as shown in Fig 5 To access error numbers 7 12 press the decimal point key this selects page 2 of 5 pressing this key again selects 3 of 5 to represent error numbers 13 18 etc To reselect page 1 after selecting page 5 further press the decimal point key The page number currently selected is shown in the level display Note cee In a GPIB controlled system the SRQ mask setting will normally be selected by a GPIB instruction sent by the controiler CARRIER FREQUENCY Error numbers 6 5 4 3 2 1 page 12 11 10 19 8 7 page 18 17 16 15 14 13 page 24 23 22 21 20 19 page 30 29 28 27 26 25 page in DUN ee Fig 5 SRQ mask setting display 30 Binary entry is entered via the keyboard and ones or zeroes rotate in from the right Enter a bit 1 to mask the required error s When these are in position press the STORE key to terminate the entry Fig 5 shows the mask set co ignore a GPIB bus error Error No 05 Chap 3 Pag
14. the carrier frequency in MHz for carrier frequencies above 2 03125 MHz subject to a maximum available phase modulation index of 999 radians Internal modulation oscillator or external modulation may be selected by the front panel keyboard 3 digit l c d see under keyboard and display 50 Hz to 10 kHz 1 dBw r t to 1 kHz 5 excluding residual phase modulation Feb 85 Am 2 Characteristic External modulation Distortion Amplitude modulation 19 Range Selection Display Accuracy Frequency response Frequency response Envelope distortion ILS performance Jun 84 H 52018 910P Vol A Performance With modulation a l c on the deviation is calibrated for input levels between 0 8 V and 1 2 V ped With modulation a l c off the deviation is calibrated for an input level of 1 V p d HI or LO l e d s are provided as an aid to maintain calibrated modulation in the a l c off mode Input impedance is nominally 100 kQ lt 3 total narmonic distortion at 1 kHz modulating frequency and at maximun deviation equal to the carrier frequency in MHz at any carrier frequency O to 99 in 1 steps Internal modulation oscillator or external modulation input may be selected 2 digit l ced see under keyboard and display Better than 4 of depth setting 1 for modulation depths up to 954 and 1 kHz modulating frequency for carrier frequencies up to 400 MHz dB f
15. the delay can be achieved by keeping the UP key continuously pressed allowing the instrument to increment then following this selection press the DOWN key also When the UP key is released the instrument will immediately decrement A reversal from down to up without delay can then be achieved by pressing the UP key before releasing the DOWN key and when the DOWN key is released the instrument will then immediately increment 4 To find the total shift from the original setting press the TOTAL shift key While this key is pressed all the displays will show the total shift of each function from their starting values To return to the initial value of the selected function press the RETURN key GREP Jun 84 H 52018 910P Vols 1 Internal modulation source a 300 400 500 ce sr 8 The internal AF modulation oscillator frequency can be controlled by successive presses of the AF OSC key The six l e d s adjacent to the AF OSC key will indicate the oscillator frequency selected 3k 1k 4 N Setting a f level l 9 Entry is similar to the r f level selection both logarithmic and linear scales are available Linear scale is always p d and logarithmic is dBm into 600 2 Units can be converted in the same manner as the r f level units Data is displayed in the level display modulation and carrier frequency are kept blank at this time A levei of 1 V rem s is set at the Power on default mode or a differe
16. to 1040 MHz lt 60 dBe at offset frequencies greater than 3 kHz for carrier frequencies from 80 kHz to 2 03125 MHz Jun 84 Characteristic Residual f m Single side band phase noise RF leakage Frequency modulation 17 Jun Range Selection Display Deviation accuracy Frequency response Frequency response 84 H 52018 910P Vols 1 Performance Less than 6 Hz r m se in CCITT telephone psophometric band at 520 MHz and improving by approximately 6 dB octave with reducing carrier frequency down to 2 03126 MHz Better than 130 dBc Hz at 90 MHz and 20 kHz offset from carrier Less than 0 5 uV ped generated in a 50 Q load by a 2 turn 25 mm loop 25 mm or more from the case of the generator with the output level set to less than 10 dBm and the output terminated in a 50 2 sealed load i Peak deviation from 0 Hz to up to 1 of carrier frequency for carrier frequencies from 2 03126 MHz to 1040 MHz ii Peak deviation from 0 Hz to 100 kHz for carrier frequencies up to 2 03125 MHz Internal modulation oscillator or external modulation input may be selected by the Front panel keyboard 3 digit l ced see under keyboard and displays 54 of deviation at 1 kHz modulating frequency excluding residual f m dB from 50 Hz to 100 kHz relative to l1 kHz Usable down to 10 Hz with reduced deviation EXTENDED FM VARIANTS 1 dB from 50 Hz to 100 kHz relative to I kHz
17. using 2018A 19A where parameters are the same as the 2018 19 series Unlock to first level as described in para 25 and select SECOND FUNCT and the numerals l and 5 The carrier frequency window will then display the current selection 0 for 2018A GPIB set or 1 for 2018 GPIB set To select 2018A press the numeral 0 key to select 2018 press the numeral 1 key Terminate the selection by pressing the STORE key Second function 16 Recall STORE 10 at switch on ao a 39 This facility allows the instrument to be operated in a remote or unattended location with a pre selected set of conditions which will remain unchanged in the event of inadvertent switching off and on of the input supply voltage In the normal operating mode if this happens the instrument would resume the initial operating mode that is CARRIER FREQ 520 MHz 20194 1040 MHz internal MOD OSC 1 kHz no MODULATION and minimum RF LEVEL 127 dBm or equivalent These conditions can be superseded by storing the Chap 3 Oct 84 Am 1 Page 17 H 52018 910P Vols 4 reguired operating conditions into STORE 10 and carrying out an automatic recall of the STORE 10 settings using the Second function 16 mode 1 First select by means of the front panel keyboard the required CARRIER FREQ MODULATION and RF LEVEL settings 2 Press the STORE key followed by the numerals 10 3 Complete the unlocking procedure gi
18. 19A an additional band 520 1040 MHz One offset value may be set for each frequency band as follows eed fo Offset on fe Offset off Selection on or off is made with the above keys 1 selecting offset on or 0O offset off Indication of the selected state is displayed in the frequency display window with either a 1 or 0 as appropriate Having set the Offset ON select either the UP or the DOWN key to increment or decrement the r f level by 0 1 dB Each successive UP or DOWN selection will then increment or decrement the r f by a further 0 1 dB When sufficient offset has been determined press the STORE key to finalize the selection which will together with the offsets on selection remain valid until further adjustment is made If an offset value of 0 1 dB is selected when the instrument is set to the limit of its operating range i e 13 dBm or Chap 3 Jun 84 Page 15 H 52018 910P Vol 1 equivalent a maximum r f level of 12 9 dBm will be imposed a further 0 1 dB offset increment will decrease this to 12 8 dBm Note eos When an offset value has been selected and stored it will remain valid for all subsequent power on sequences RF level accuracy of the instrument is therefore impaired and care should be taken to account for this Second function 9 Elapsed time display m a 33 This facility enables the user to observe the total number of instrumen
19. 25 mm 20 7 in Weight 16 kg 35 2 1b ACCESSORIES Supplied accessories 31 AC supply lead Operating manual H 52018 910P Vol 1 Front panel blanking kit Optional accessories 32 Service manual H 52018 910P Vol 2 GPIB module Maintenance kit includes r f extender cables l c ed insertion and extraction tools etc Rack mounting kit Front handle kit GPIB manual H 54811 O10P Contains details of general GPIB protocols GPIB lead assy GPIB IEEE IEC connector adapter RF connecting cable TM 4969 3 502 1 5 m 5 ft BNC RF coaxial cable N to N type Impedance adapter 50 75 Q Feb 85 Am 2 Code no 43123 0 76Y 46881 511A 46883 654E 46881 5122 54433 0010 54711 0335 46883 506M 46883 511R 46881 365R 43129 189U 46883 408K 43126 0125 54311 095C 54411 051X Chap 1 Page 15 Para SON i We Fig H 52016 910P Vol 1 Chapter 2 INSTALLATION CONTENTS Unpacking and repacking Mounting arrangements Connecting to supply Safety testing GPIB interface Rack mounting Front panel handles Page Voltage ranges 928 0 9S 9 o 8 8 d 99o a 39 d2 9 L E 8 3 UNPACKING AND REPACKING OTTE aie Aa E OAE E A D AA E POO lt a NE 0 ARE E PAE EOP SE EA A e E AEE S la Retain the container packing material and the packing instruction note if included in case it is necessary to reship the instrument 2 If the instrument is to be returned for servicing attach a label indica
20. E NUMBER CARRIER FREQUENCY MODULATION X ff Le bn al LEVEL 183 __ SERIAL NUMBER vf qf bt Fig 6 Read identity display Chap 3 Page 16 Jun 84 H 52018 910P Vol 1 Second function 12 Write user definable string 35 This is a GPIB only facility whereby a string of data may be set at the user s convenience details are given in the GPIB functions 5F12 paragraph Second function 13 Read user definable string 36 This read only facility provides the means of reading back data set by means of the GPIB SF12 write facility and like Second function 12 this is used only in conjunction with GPIB see GPIB functions 5F13 paragraph Second function 14 1 or 10 MHz standard setting 37 This function allows the user to select either 1 MHz or 10 MHz internal frequency standard First carry out the unlocking procedure given in para 25 then select SECOND FUNCT and the numeral keys 1 and 4 The frequency standard currently selected is then displayed in the carrier frequency window display shows 1 MHz or 10 MHz To 1 MHz std press the numeral ae 1 or 0 to select 10 MHz std eciisned by the STORE key Second function 15 Old new GPIB command set 38 This function is of use in automatic test areas where a 2018A or a 2019A is required for test purposes to be addressed with a 2018 or 2019 set of instructions This allows a full range of tests to be carried out
21. Locked 1 2 Unlocked to lst or 2nd level Log units 0 6 see Second function 5 para for details Linear units 7 8 see Second function 5 para for details TC a ET OD a a SF AE PGES fo SED LY ACE PR ES PR IO A a a 63 The identity string accessed by SF11 QU allows instrument type number software issue number and serial number to be read by the controller The information is stored in non volatile memory and in 2018A is also used to tell the software which version of instrument it is to drive The string is displayed as described under second function 1l Each data field is delimited by one space SFl2 User string write facility 64 Up to 32 ASCII characters can be stored in non volatile memory by the user This bus only facility is useful for recording such information as date next calibration is due test gear numbers etc The string is terminated by the LINEFEED character ASCII code 10 which is included as the last character stored If an attempt is made to store too many characters then lt lf gt is automatically inserted as the 32nd SF13 QU User string read facility 65 This facility provides a means of reading back data set by means of SF12 write facility and is again a bus only facility Service requests CSRQ _ 66 The 2018A can request service to warn the controller of certain error conditions In response to a serial poll after asserting the SRQ line the 2018A will provide a status word 8 bits in which bit 6 is set to
22. Operating Manual H 52018 910P Vol l Signal Generators 2018A and 2019A 80 kHz 520 MHz 80 kHz 1040 MHz Code No 52018 910P Code No 52019 910E and combination versions and combination versions in 2018 400 series in 2019 400 series from 52018 401R from 52019 401L to 52018 413N to 52019 413P Marconi Instruments Ltd 1984 Printed in the UK Part No 46881 511A Print code F 10 86 MI 6 0c Feb 85 Am 2 Page i H 52018 910P Vol 1 CONTENTS PRELIMINARIES Title page Contents Notes and cautions CHAPTERS General information Installation Operation Technical description Maintenance These chapters are contained in a Replaceable parts separate volume available as an Servicing diagrams optional extra Modifications and supplements CONDUFWNHE HAZARD WARNING SYMBOLS Note Page The following symbols appear on the equipment Symbol Type of hazard Reference in manual A Static sensitive device Page iv Component containing beryllia Page iv Each page bears the date of the original issue or the code number and date of the latest amendment Am 1 AM 2 etc New or amended material of technical importance intruduced by the latest amendment is indicated by triangles positioned thus p e to show the extent of the change When a chapter is reissued the triangles do not appear Any changes subsequent to the latest amendment state of the manual are included on inserted sheets coded Cl C2
23. PIB interface 25 Capabilities Environmental H 52018 910P Vol 1 Performance A GPIB interface is available as an optional accessory and can be easily fitted by the user All functions except the SUPPLY ON switch are remotely program mable In addition to allowing full GPIB control of the instrument the GPIB module has an auxiliary output socket which can be used to control relays etc Complies with the following subsets as defined in IEEE 488 1978 and IEC Publication 625 1 SHl AH1 T6 TEO L4 LEO SR1 RLI PPO DC1 DTO CO El 26 Conditions of storage and transport Temperature Humidity Altitude Rated range of use Over which full specification is met Temperature Safety 2 Radio frequency interference 28 Power requirements 29 Voltage Frequency Consumption Chap 1 Page 14 409C to 70 C Up to 904 relative humidity Up to 2500 m pressurized freight at 27 kPa differential i e 3 9 lbf in 0 to 550C Complies with Publication IEC 348 Conforms to the requirements of EEC Directive 76 889 as to limits of r f interference AC supply Voltage ranges switchable 105 V 120 V i 210 v 240 y 10 45 Hz 440 HZ o 85 VA maximum Jun 84 Characteristic Performance H3520 18 91r0P Vol l Weight and dimensions over projections but excluding optional front panel handles 30 Height 152 mm 6 in Width 425 mm 16 7 in Depth 5
24. acy 2 dB from 1 5 MHz t2 dB from 1 5 MHz to 5 MHz to 5 MHz dB from 5 MHz 1 dB from 5 MHz to 520 MHz to 520 MHz 2 dB from 520 MHz to 1040 MHz 10 kHz CARRIER VARIANTS Level accuracy 1 dB from 10 kHz dB from 10 kHz to 520 MHz to 520 MHz 2 dB from 520 MHz to LO4OMHz Chap 1 Page 4 Jun 84 H 52018 910P Vole 1 Characteristic Performance 2018A version 2019A version PULSE MOD VARIANTS Level accuracy dB from 80 kHz With pulse mod to 520 MHz not selected Level accuracy 1 5 dB from 10 MHz With pulse mod to 520 MHz selected and 5V applied to input i e Carrier on Note cee dB from 80 kHz to 520 MHz 3 dB from 520 MHz to 1040 MHz tle 4 5 dB from 10 MHz to 520 MHz dB from 520 MHz to 1040MHz With pulse mod selected the maximum output level is reduced to 3 dBm VSWR Reel for output levels below 300 mV O lt iis fy Spurious signals ll Harmonically lt 30 dBc for related signals carrier fre for output levels quencies from lt 1 V eomef 80 kHz to 520 MHz Sub harmonics None Frequency modulation 12 Resolution 3 digits or 10 Hz whic ever is the larger up to 520 MHz Jun 84 lt 30 from lt 20 from lt 20 from h l up to 520 MHz 1 520 MHz to 1040 MHz dBe for carrier frequencies 80 kHz to 520 MHz dBe for carrier frequencies 520 MHz to 1040 MHz dBe for carrier frequencies 520 MHz to 1040 MHz 3 digits or 10 Hz which ever is the lar
25. at 520 MHz carrier frequency and then to gt 35 dB at 800 MHz carrier frequency usable to 1040 MHz Typically 280 ns Rear panel BNC connector Input impedance 50 2 Nominal signal levels O V for carrier off 5 V for carrier on Pulse modulation is selected by pressing M ULSE simultaneously followed by the MOD ON OFF key The modulation window then displays P and EXT AM the two keys l PULSE p 300 Hz 400 Hz 500 Hz 1 kHz 3 kHz and 6 kHz selected sequentially by repetitive pressing of the AF OSC key Six l e d s indicate selected frequency t5 A front panel BNC socket provides an output for the AF signal Jun 84 Characteristic Output level selection Output level accuracy Maximum output Distortion Source impedance Frequency standard 22 Frequency standard Input Out put Internal standard Temperature stability Warm up time Jun 84 H 52018 910P Vol l1 Performance Oel mV to 5 V r m s selected by keyboard entry Output may be entered in mV V or as dBm into 600 2 Conversion between dB and voltage units may be achieved by pressing the appropriate key dB mV V The output frequency is always that of the AF OSC and is short circuit proof At switch on the AF level is set to 1 V 5 above 50 mV r emes 104 from 0 5 mV to 50 mV r m s Capable of driving a 2 kQ load for output levels up to 5 V rem s Capable of driving a 600 2 load for output levels up to 2 V rem s
26. ation 2018A 2019A 14 Carrier frequency 15 RF output 16 Spurious signals 17 Frequency modulation 18 Phase modulation 19 Amplitude modulation 20 Pulse modulation 21 AF oscillator 22 Frequency standard 23 Auxiliary inputs and outputs 24 Keyboard and displays 25 GPIB interface 26 Environmental 21 Safety 28 Radio frequency interference 29 Power requirements 30 Weight and dimensions 31 Accessories 31 Supplied accessories 32 Optional accessories Fig Page 1 80 kHz to 1040 MHz AM FM Synthesized Signal Generator 2019A ee 2 FEATURES l 2018A and 2019A are stable a m f m synthesized signal generators 2018A covers the frequency range 80 kHz to 520 MHz 2019A includes a frequency doubler which increases the frequency range to 1040 MHz Both are phase locked to a frequency standard and can be set to a resolution of 10 Hz at frequencies up to 520 MHz and in the case of 2019A resolution of 20 Hz for frequencies above 520 MHz Chap 1 Jun 84 Page 1 H 52018 910P Vol 1 b i ee a ARCOM INETHOMENTS ana TOE sr ma p a mo 4 as L le a cals m Fig 1 80 kHz to 1040 MHz AM FM Synthesized Signal Generator 20194A Le Front panel operation is carried out by direct entry of required settings via the keyboard Microprocessor control ensures maximum flexibility and allows programming by the General Purpose Interface Bus GPIB This facility is offered as an optional accessory enabling the instrument to be used both
27. d edges care should be taken particularly when servicing the equipment to avoid minor cuts WARNING TOXIC HAZARD Many of the electronic components used in this equipment employ resins and other chemicals which give off toxic fumes on incineration Appropriate precautions should therefore be taken in the disposal of these items Page iv Jun 84 H 52018 910P Vol 1 A Beryllia beryllium oxide is used in the construction of the following Jun components in this equipment Unit AC4 Transistor TRILO This material when in the form of fine dust or vapour and inhaled into the lungs can cause a respiratory disease In its solid form as used here it can be handled quite safely although it is prudent to avoid handling conditions which promote dust formation by surface abrasion Because of this hazard you are advised to be very careful in removing and disposing of these components Do not put them in the general industrial or domestic waste or despatch them by post They must be separately and securely packed and clearly identified to show the nature of the hazard and then disposed of in a safe manner by an authorized toxic waste contractor 84 Page v H 52013 910P Vol 1 Chapter l GENERAL INFORMATION CONTENTS Para l1 Features 3 Out put 4 Modulation 5 Front panel 7 Variants 2018A 2019A 8 Performance data 9 Carrier frequency 2018A 2019A 10 RF output 2018A 2019A 11 Spurious signals 2018A 2019A 12 Frequency modul
28. der is also advisable MOUNTING ARRANGEMENTS 3 Excessive temperatures may affect the instrument s performance therefore completely remove the plastic cover if one is supplied over the case and avoid standing the instrument on or close Eo other equipment that is hot praia A AIRES Sa NE RS A SN a E 4 Before connecting the instrument to the a c supply check the position of the two voltage selector switches on the rear panel A locking plate fixes both switches into one of four possible combinations and only the selected voltage range is displayed when the locking plate is fixed to the back panel The instrument is normally despatched with the switches selected to 230 240 V To select a different voltage range remove the locking plate and re position the switches to the required range as shown in Fig 1 below and refit tne locking plate into its alternative position Note eee The a c supply fuse may also have to be changed An indication of the correct fuse rating is given with each displayed voltage range i e 1 A T 1 amp time lag 105 V 120 V 102 0 5 A T 0 5 amp time lay 210 V 240 V 102 The fuses are 20 mm x 5 m cartridge type De The free a c supply cable is fitted at one end with a female plug which mates with the a c connector at the rear of the instrument When fitting a supply plug ensure that conductors are connected as follows Earth Green yellow Neutral Blue Live Brown When attaching the
29. e 14 Oct 84 Am 1 H 52018 910P Vol 1 Second function 5 RF level units setting a Pee Le 31 Unlock the instrument to the first level of operation completing the unlocking procedure given in para 25 then select SECOND FUNCT and the numeral 5 keys On entering second function 5 two digits are displayed in the r f level display These represent the two scales of r f level units which are currently selected the left hand digit represents the logarithmic scales and the right hand digit the linear scales as shown below Left digit logarithmic scale Right digit linear scale Oy lt aBV em f ie Sel l dBmV e m f Ss Peds 2 dBuv e m f 3 dBV Dads 4 dBmV p d 5 dBuV pedo 6 dBm These units may be selected via the keyboard by entering the numbers corresponding to the units required and then pressing the STORE key Second function 6 RF level offsets mae eer Ld 32 First select a carrier frequency within the chosen band see below followed by a suitable r f level Complete the unlocking procedure given in para 25 then select SECOND FUNCT and numeral 6 keys In addition to the standard calibration for r f output level the instrument has a capability for overall level adjustment to facilitate matching with other equipment The output level can be raised or lowered by approximately 2 dB in the offset mode In 2018A there are two carrier frequency bands 0 260 MHz and 260 520 MHz and in 20
30. ed If an error is made in the entry re selection of the function key will clear the previous entry Complete the entry by press ing the appropriate UNITS terminator key If a request outside the operating range of the instrument is made a LIMIT annunciator will be set on the rele vant display and the generator will tune to either the minimum or the maximum value nearest to the initial request One exception to this is if a carrier frequency less than 80 kHz is selected for details see next para Setting a carrier frequency eal Ea 6 If the l e d in the orange CARRIER FREQ key is off press the CARRIER FREQ key If the l e d is on this will not be necessary Enter the required value via the numerical key pad including the decimal point if required the data entered will appear in the carrier frequency display Terminate the instruction by pressing the appropriate UNITS terminator key If a request lower than the minimum specified frequency 80 kHz is made the LIMIT annucia tor is displayed and the instrument tunes to the requested frequency but with a degraded performance When selections below 30 kHz are made the accuracy Chap 3 Jun 84 Page 5 H 52018 910P Vol 1l of the ref level output will be impaired Subsequent OFF ON control is achieved by operation of the CARRIER ON OFF key Note eee If the 10 kHz Carrier frequency variant is fitted the accuracy of the selected output level will be accurate down to the low
31. en used In this event pressing the TOTAL SHIFT key will give a valid display of the total shift in the appropriate window This facility is of value when secrecy is important SECOND FUNCTION OPERATIONS 23 Second function operations provide a means of controlling various secondary features and calibrations within the instrument Access to many of these operations is generally not required during routine use of the instrument and some should only be accessed by skilled personnel during the course of realignment fault finding or repair There are three levels of Operation as follows 1 Normal operation second functions 0 1 2 3 4 9 11 12 13 and 18 are unprotected and can be accessed directly 2 First level operation second functions 5 6 14 15 and 16 have a first degree protection Access to this level can be gained after operating an unlocking procedure described in para 25 3 Second level operation second functions 7 8 9 10 17 190 191 and 192 have second degree protection and can only be accessed by the operation of a special key code Details of the code are given in the Service Manual 24 In general the second function mode is entered by pressing the blue SECOND FUNCT key followed by the numerals corresponding to the second function required Pressing the second function key inhibits the action of some keys however the instrument can always be restored to its normal operating mode by pressing any of the orange functi
32. er specified limit of 10 kHz If the Avionics variant is fitted then the lowest specified limit is 1 5 MHz incrementing and decrementing Cc oo G a Co Fs FREQ le To display current increment values press the orange key identified by a delta sign A Initially the instrument will automatically select and display an increment for each of the main functions as follows Carrier frequency 1 kHz Modulation either FM 1 kHz M 1 Rad or AM 1 RF level 1 dB and AF level 1 dB If an AF level increment is required selecting A AF LEVEL causes the LEVEL window indication to change from the RF level increment initially displayed to that of the requested AF level increment To return the instrument to normal operation without affecting any current increment value that may have been selected press any function key twice To enter a new value of increment such as a carrier frequency step of 10 kHz press the keys shown in the example above FM M AM AF or RF LEVEL may be similarly incremented note that if incrementing the RF LEVEL the only valid terminator is the dB key a 1 Each press of the UP key will then increment the carrier frequency by 10 kHz likewise pressing the DOWN key will decrement the carrier frequency by a similar amount 2 Holding the UP or DOWN key pressed will result in continuous incrementing or decrementing after a brief delay 3 Changing from the incrementing mode to the decrementing mode without
33. etc ii Jun 84 H 52018 910P Vol 1 NOTES AND CAUTIONS ELECTRICAL SAFETY PRECAUTIONS This equipment is protected in accordance with IEC Safety Class l It has been designed and tested according to IEC Publication 348 Safety Requirements for Electronic Measuring Apparatus and has been supplied in a safe condition The following precautions must be observed by the user to ensure safe operation and to retain the equipment in a safe condition Defects and abnormal stresses Whenever it is likely that protection has been impaired for example as a result of damage caused by severe conditions of transport or storage the equipment shall be made inoperative and be secured against any unintended operation Removal of covers Removal of the covers is likely to expose live parts although reasonable precautions have been taken in the design of the equipment to shield such parts The equipment shall be disconnected from the supply before carrying out any adjustment replacement or maintenance and repair during which the equipment shall be opened If any adjustment maintenance or repair under voltage is inevitable it shall only be carried out by a skilled person who is aware of the hazard involved Note that capacitors inside the equipment may still be charged when the equipment has been disconnected from the supply Before carrying out any work inside the equipment capacitors connected to high voltage points should be dischar
34. eviously fitted 10 Fit rack brackets in front panel handles or side trim recesses using M4 x 16 pan head screws and washers finally refit top and bottom covers When fitting the unit into the rack support at the rear should also be given e g a shelf located within the rack or cubicle 2 4 Jun 84 H 52018 910P Vol 1 FRONT PANEL HANDLES CSR a e SD 20 EL A RD a eS DED 9 Front handles are supplied only as optional accessories fitting instructions are as follows Jun 1 Remove the side trim infills and side trims Discard the side trims but retain the side trim infills screws and washers for re use Position the instrument on its side 2 Fit the panel handles without the side trim infills first aligning all four screws Tighten down the two inner screws and washers and remove the two outer screws 3 Refit the side trim infills replace the outer two screws and washers and tighten down Chap 2 84 Page 5 Para l O ourn amp FW LY 67 June H 52018 910P Vol 1l Chapter 3 OPERATION CONTENTS Principles of control Front panel control Rear panel control Preparation for use Switching on Operating procedures Setting a carrier frequency Incrementing and decrementing Internal modulation source Setting a f level External modulation Setting f m setting gt m Auxiliary f m input socket setting a m setting r f level setting pulse modulation On Off keys
35. f a new address is required this may be entered via the keyboard Numbers rotate in from the right When the required address is displayed pressing the key will if the address is acceptable 00 30 replace the previous one If the address is too large it will be ignored and the current address re displayed instead Except for second function 1 where the display has an alternative use current second function selection is normally shown in the modulation window Second function 3 Manual latch setting 28 This function allows an 8 bit binary instruction to be directed to any of the instruments internal latches for testing and fault finding On entering the latch address i e A L1 current data on the latch is displayed in Chap 3 Jun 84 Page 13 H 52018 910P Vol 1 binary in the Carrier frequency display Information is entered from the left and rotates to the right A decimal point indicates the pointer between old and new data Pressing the STORE key sends the displayed data to the latch This facility is fully described in the Service manual and is an invaluable aid when diagnosing internal instrument bus or latch faults On exiting from second function 3 all latch data which may have been over written is restored Second function 4 SRQ mask setting FEE E 29 Select SECOND FUNCT mode followed by the numeral 4 The SRQ mask allows an instruction to be made for the instrument not to request service over
36. ff keys_ CARRIER ON OFF ee 17 Each of the above keys may be operated independently of the function key to allow control of r f output a f output or modulation ON OFF control is carried out by the toggle action of each key Reverse power protection 18 The instrument is protected from accidental application of reverse power if the reverse power protection RPP unit is tripped the integral RF LEVEL lee d will flash and the REV PWR LIMIT annunciator will be set on the RF LEVEL display During this time the keyboard will not respond except to reset commands After the source of power has been disconnected the RPP is reset by pressing the RF LEVEL function key When the instrument is switched OFF the output socket is automatically disconnected from the output attenuator a further safety feature Store and recall Ee oo 19 The instrument has 100 non volatile stores available Stores numbered 00 19 store complete instrument settings including increment values Stores 20 99 store settings of carrier frequency only Store key selection is indicated by an integral l e d and the store number currently selected is displayed in the levels window 1 To store press STORE followed by a two digit numerical entry 2 To recall press RECALL and the appropriate numerals Increment keys can be used to sequence the recall of stores if required 20 To store a set of modulation and r f levels that can be a
37. further less commonly used facilities 10 RF OUTPUT 50 2 N type output socket Indication of the r f level is shown on the RF LEVEL display 11 AF OUTPUT This is a low impedance output at the frequency selected by the internal AF OSC control and is available when either INT or EXT modulation is selected This allows the testing of transceiver audio circuits microphone inputs etc Rear panel control 3 1 REMOTE CONTROL GPIB INTERFACE This optional accessory allows remote control of the instrument and in addition has an auxiliary output socket which can be used to control relays etc Accepts the 24 way IEEE GPIB connector 2 MOD INPUT RF OUT These blanked holes provide alternative fittings when the instrument is rack mounted Fitting instructions are included in Chaps 2s 3 PULSE MOD IN This blanked hole is used only if the pulse modulator option is fitted 4 STD FREQ IN OUT BNC socket provides an output from one of two possible internal reference standard frequencies 1 MHz or 10 MHz or alternatively allows the use of a 1 MHz or 10 MHz external reference The required function is selected by the front panel keys If EXT STD Chap 3 Feb 85 Am 2 Page 3 H 52018 910P Vol l is selected when power is initially applied Error No 15 will be displayed in the carrier frequency window After a delay of approximately one minute the external and internal frequencies will synchronize and the error number will be removed Sub
38. ged to discharge mains filter capacitors if fitted short together the L live and N neutral pins of the mains plug Mains plug The mains plug shall only be inserted in a socket outlet provided with a protective earth contact The protective action shall not be negated by the use of an extension lead without protective conductor Any interruption of the protective conductor inside or outside the equipment is likely to make the equipment dangerous Fuses Note that there is a supply fuse in both the live and neutral wires of the supply lead If only one of these fuses should rupture certain parts of the equipment could remain at supply potential To provide protection against breakdown of the supply lead its connectors and filter where fitted an external supply fuse e g fitted to the connecting plug should be used in the live lead The fuse should have a continuous rating not exceeding 6 A Make sure that only fuses with the required rated current and of the specified type are used for replacement The use of mended fuses and the short circuiting of fuse holders shall be avoided Jun 84 Page iii H 52018 910P Vol 1 RADIO FREQUENCY INTERFERENCE This equipment conforms with the requirements of IEC Directive 76 889 as to limits of r f interference CAUTION STATIC SENSITIVE COMPONENTS Components identified with the symbol on the circuit diagrams and or parts lists are static sensitive devices The presence of s
39. ger up to 520 MHz 3 digits or 20 Hz which ever is the larger up to 1040 MHz Chap l Page 5 Characteristic 13 The remaining characteristics are Carrier frequency 14 Selection Frequency indication Accuracy RF output 15 Level Selection Display Resolution Output impedance Reverse power protection Spurious signals 16 Non harmonically related Signals Chap 1 Page 6 H S20 16 9 1 0P Vol 1 Performance common to both 2018A and 2019A By keyboard entry 8 digit l cC d for details see under Keyboard and displays Equal to the frequency standard accuracy see under Frequency standard 0 2 uV to 2 V oM f 127 to 13 dBm in cowe and m modes 0 2 uV to 1 V eomef 127 to 7 dBm when ame is selected By keyboard entry units may be uV mV V omof Or ped Or dB relative to 1 uV 1 mV 1 V M Or pode Or dBm Conversion between dB and voltage units may be achieved by pressing the appropriate unit key dB or V mV uV 4 digit l c d with units annunciators see under Keyboard and displays 0 1 dB or better over entire voltage range 50 2 Type N female MIG 29012730 socket to An electronic trip protects the generator output against reverse power of up to 50 W from d c to 1 GHz The trip may be reset from the front panel or via the GPIB lt 70 dBe at offset frequencies greater than 3 kHz for carrier frequencies from 2 03126 MHz
40. iary output plug and socket connections Chap 3 Page 18 Jun 84 H 52018 910P Vol 1 2 Data is set on the pins in the same manner as Second function 3 Manual latch setting Current data if any is displayed in the carrier fre quency window New data is entered in binary using the front panel 707 and 1 keys most significant bit first 3 I the outputs are to be connected to a load that has its own integral 5 V supply line available it is preferable to connect this to the enable line on pin 10 pins 6 7 and 9 are internally connected to earth In the event of an external power failure the enable circuit will then be set low and the data lines disabled Second functions 7 8 9 10 17 190 191 and 192 Second level operation 41 All the following facilities have second degree protection further information on these facilities and details of the special key code to access them are contained in the Service manual RF level calibration FM tracking Reset of elapsed time display Read total instrument operating time Second function 17 Calculation and storage of amended EAROM checksum Second function 190 Write identity string setting second function 191 Protection of store settings Second function 192 Display blanking of recalled stores Second function Second function Second function Second function O oO co N p OPERATION WITH 75 Q LOADS 42 The performance specification for tne ins
41. ilar use of QU when the function is engaged the format being numeric strings only for calibration data etc e g FM tracking and a numeric string representing hours for the elapsed time iadicator Three further data strings are avail able Status string Identity string and a User string these are accessed by means of second function controls and the QU function 60 The external modulation input level status indicated by the front panel HI and LO 1l e d s can also be accessed on receipt of the QL command The current Level is transferred to the GPIB output using two ASCII characters to indicate one of the three possible states HL input too high LO input too low OK input within range 61 Requesting a string to be output will overwrite any stri ig data waiting to be sent Addressing the instrument to talk without specifying a string to be sent or re addressing to talk after a string has been completed will result in an error and SRQ if not masked Chap 3 Jun 84 Page 23 H 52018 910P Vol 1 SFl QU Status string 62 When accessed by SF1 QU the status of the instrument is sent to the controller each data field being delimited by one space in the following format 2Z018A cs XX u X Lu X ts X Li X u X or GPIB OFFSETS FREQ STD LEVEL OF LOG LINEAR 2019A ADDRESS ON OFF 1 10 MHZ PROTECTION UNITS UNITS GPIB Address 00 30 Offsets on 17 off 707 1 MHz std 1 10 MHz std 0 Level of protection 0
42. ines The sequence is initiated when the function becomes active and the purpose of the function is to synchronize the rate at which bytes become available to the rate at which accepting devices on the bus can receive the data 46 AH Acceptor handshake complete capability mr a The acceptor handshake sequences the reading of the data byte from the bus data lines 47 T6 Talker function no talk only function The talker function provides the 2018A with the ability to send device dependent messages over the bus to other devices The ability of any device to talk exists only when it has been addressed as a talker 48 L4 Listener function no listen only function The listener function provides a device with the ability to receive device dependent messages over the bus The capability only exists where the device is addressed to Listen via the bus by the controller 49 SRI Service request function complete capability n The service request function gives the 2018A the capability to inform the controller when it requires attention 50 RLI Remote local function complete capability The remote local function allows the 2018A to be controlled either by the local front panel keys or by device dependent messages over the bus 5l DCl Device clear function complete capability Device clear is a general reset and may be given to all devices in the system simultaneously DCL or only to addressed devices SDC
43. ion 6 Unsolder the yellow and orange wires from the front panel MOD IN socket and adjacent earth tag Unfasten and remove the socket from the front panel mounting remove and discard the blind grommet from the MOD IN alternative rear panel position Uncleat excessive modulation ecableform from the lower r f box and re route this to the rear panel Refix MOD IN b n ec e socket to the rear panel position Now reconnect the yellow wire to the MOD IN socket and the orange wire to the adjacent earth point Select a b en c replacement blind grommet issued with the included blanking kit and fit this into the front panel position Recleat the cable to the lower ref box 7 Disconnect the r f output connector from SKBA on ATO 1 attenuator and also the RF OUTPUT socket from the front panel assembly Withdraw the connector and socket through the front panel Similarly remove the blind grommet from the alternative rear panel RF OUT position discard this and fit the replacement N type grommet supplied in the blanking kit into the front panel position 8 Pass the r f output connector through the alternative rear panel position and secure the RF OUTPUT socket to the rear panel Re route the cable over the bottom r f box and reconnect SKBA to ATO I1 attenuator 9 Lower the top r f box and secure this reconnect PLAV to the rear of the box Replace and secure the front panel assembly and side trim also refit front handles if pr
44. n internal standard is selected and becomes the external standard input when external standard is selected The choice of 1 MHz or 10 MHz reference standard may be made by a second function control 1 MHz or 10 MHz at nominally 3 V p p Square wave Source impedance 100 2 nominal Accepts either a 1 MHz or 10 MHz signal of at least l1 V rem s Maximum recommended input level 2 5 V r em s Frequency selected by second function control Input impedance 100 2 nominal Blanked holes are provided so that the RF output and modulation input socket can be fitted to the rear panel for systems use etc These are described in Chap 3 Operation All instrument settings are controlled by the front panel keyboard The main function of the three liquid crystal displays is to provide a simultan eous readout of carrier frequency modula tion and r f level i Carrier frequency display 8 digit with annunciators to show frequency units external frequency standard frequency limit exceeded remote operation selected and instrument addressed ii Modulation display 3 digit with annunciators to show modulation units m gt m e aem e modulation off external modulation selected and modulation limit exceeded iii RF level display 4 digit with annuncilators to show ret level units r f output off reverse power trip operated and r f level limit exceeded and a f level units Chap l Page 13 Characteristic G
45. nt setting if Recall store 10 setting has been set see Second function 16 for details External modulation Ci E r04 Press FM oM or AM function key as appropriate followed by the INT EXT key to select external this is indicated on the modulation display by an EXT annunciator Further pressing the INT EXT key will return the instrument to the internal mode The external mod level is monitored and HI or LO l e d s are provided as an aid to maintain calibrated modulation in the a l c off mode Li 1 With MOD ALC ON and external modulation selected the signal from the externally applied modulation source can be set internally to the correct level providing the applied voltage is between 0 8 V and 1 2 V MOD ALC ON selection is indicated by the integral l e d 2 With MOD ALC OFF selected an input of 1 V r m s will produce the displayed modulation value The instrument will normally power up with MOD ALC off when in EXT MOD mode Chap 3 Jun 84 Page 7 H 52018 910P Vol 1 Setting f m Select the modulation frequency 300 Hz 400 Hz 500 Hz 1 kHz 3 kHz or ne as required by successive presses of the AF OSC key Continue the selection shown above to select a deviation of 20 kHz The instrument normally switches on in the Internal mode E 1 To seleet external f m first press the FM key if its l e d is not lit then press the INT EXT key The f m will then be selected to e
46. o uSe Non volatile store and recall facilities are also provided by using an electrically alterable read only memory store that does not require a battery back up system Carrier frequency f m M aem refs and a f level functions may be incremented or decremented using the up down keys 6 Second function mode of operatione This includes the means of setting the GPIB address selection of alternative r f level calibration units access to various calibration routines instrument running hours and an iden tity string that displays instrument type software issue and serial number Up to 32 ASCII characters may also be stored in non volatile memory by the user via the GPIB bus Modulation input level status information is also available via the GPIB bus if required Variants le Four individual variants are available in both 2018A and 2019A A Single option or a combination involving up to three of the four options may be fitted to the instrument these are as follows 1 Extended f m bandwidth stereo and digital signalling capability 2 Avionics providing the capability for testing VOR amp ILS 4 10 kHz Carrier frequency extended range 8 Pulse Mod ulation Single amp Combination options 52018 or 52019 1 2 4 8 401R 401L Extended f m 402B 402J Avionics 403K AQO3F Extended m Avionics 404A 404G 10 kHz Carrier 405Z 405V Extended f m 10 kHz Carrier 408U 408D _
47. o MODULATION and minimum RF LEVEL 127 dBm or equivalent The instrument may be set to the contents of store 10 if second function 16 has previously been set For details see the paragraph Recall STORE 10 at switch on Chap 3 Page 4 Feb 85 Am 2 H 52018 910P Vol 1 2 Before the initial operating mode is displayed an indication of the software issue number is shown in the level window e g 01 02 03 for approximately one second If the instrument has developed a fault condition an error number will be continuously displayed Details of these are given in the GPIB functions paragraphs 3 Check that the carrier frequency window does not indicate EXT STD unless an external frequency standard input is required If this has been inadvertently selected press CARRIER FREQ and INT EXT keys to reselect internal frequency standard 4 During normal operation the instrument s internal reference standard will give an accuracy within the rated performance after a warm up period of 5 minutes at normal ambient temperatures CARRIER FREQUENCY MODULATION LEVEL pea ter te a y ii iO aa E a E ALA LAO A L Li L he TPC4499 Fig 3 2018A initial operating mode OPERATING PROCEDURES 5 Selection of data is carried out by first pressing the required function key and this is then indicated by an integral l e d Follow this with the numerals including a decimal point or negative sign if required a positive sign is otherwise impli
48. o personnel who have a full knowledge of these operations and require access to them in the course of realignment fault finding or repair only If inadvertent selections are made it is possible to invalidate the instrument s calibration 2 The instrument always reverts to the locked state after using the bus Second function 1 Status 26 Entering Second function 1 will result in the instrument displaying status information as shown below in Fig 4 Chap 3 Page 12 Jun 84 H 52018 910P Vos J CARRIER FREQUENCY MODULATION LEVEL at OT be dat CUD i e 2018A or 2019A GPIB Address RF Level RF Level RF Level as appropriate or if calibration off set Logarithmic scales Linear scales the GPIB option currently in use O dBV e m f 7 e mM f is not fitted 0 Offsets off 1 dBmV e m f 8 p d 1 Offsets on 2 dBuv e m f 3 dBV p d 4 dBmV p d l or 10 MHz 5 dBuV ped Standard selected 6 dBm 0 10 MHz 1 1 MHz Shows the state of the second function lock mode Note e 0 Locked 1 Unlocked to first level No data can be altered under 2 Unlocked to second level Second function 1 Fig 4 2018A Second function 1 status mode Second function 2 GPIB address setting 27 If the GPIB option is not fitted the sign is displayed in the carrier frequency display otherwise the current GPIB address is displayed I
49. on keys This means of exit from second function operation is always safe i e it will not corrupt any data or alter any status bits and the displays will revert to their normal functions Chap 3 Jun 84 Page ll H 52018 910P Vol 1 No data will be permanently altered unless the store key is pressed The operation of each of the secondary functions is as follows Second function 0 Unlock 25 Switching on the instrument automatically sets all second functions with first and second degree protection to the Locked mode Normal operation only can then be accessed directly To gain access to the First level operation press the SECOND FUNCT and 0 keys followed by the MOD ALC and AF ON OFF keys both of which must be pressed simultaneously until a 1 appears in the CARRIER FREQUENCY window The instrument will then be unlocked at the First level and allow further selection of the required second function in that group If the sequence is in error or aborted part way through the instrument will remain locked Once unlocked the instrument remains so until either the SECOND FUNCT and 0 keys are once more pressed or until the instrument power is switched off Notes eee 1 Access to all levels of operation is always available over the GPIB where fitted Care must therefore be taken when selection of either First or Second level operations are required Access to second functions via GPIB selection should be restricted t
50. pplied to any carrier frequency first enter a carrier frequency of O Hz followed by the required modulation and r f level values Press the STORE key followed by one of the instrument store numbers 00 to 19 to retain the settings Subsequently recalling the store with the RECALL key will retrieve the modulation and r f level leaving the current setting of carrier frequency selected This is a useful method of transferring a standard set of modulation level settings onto carrier frequencies entered by the operator Chap 3 Page 10 Jun 84 H 52018 910P Vol 1 Storing CF 0 Hz will enable the Carrier frequency currently displayed being kept when the store is recalled Store 10 can be used to implement a pre selected set of conditions when power on is initiated For details of this facility see the paragraph Second function 16 21 Access to stores may be protected using second function 191 Any attempt to over write a store will result in Error number 11 being displayed in the carrier frequency window Digital information within the store will be retained Details of this second level operation are given in Vol 2 Service Manual 22 Another second level operation second function 192 can be used to disable carrier frequency modulation and level displays when Stores 01 to 99 are recalled Recall store 00 will always produce a valid display As Stores are recalled all display windows will remain blank unless incremental values have be
51. r case ASCII format Where possible these codes correspond directly to the front panel keys however where the normal front panel control requires a knowledge of the previous state of the instrument e g toggling controls such as on off special codes are provided to simplify programming 50 In order to improve the readability of control strings the codes may be separated by commas or spaces after each code pair or data group These are ignored by the instrument When data is entered the syntax is the same over the GPIB as that used in control from the front panel For example to enter a complex string of instructions such as a carrier frequency of 123 45 MHz with an increment of 25 kHz and an r f level of 1 2 uV the string can be sent as follows CF 123 45 MZ DE CF 25 KZ LV 1 2 UV Or similarly if it re quired to change the r f level units setting to dBm second function mode 5 logarithmic scale 6 the string SF 5 6 ST should be sent 57 The ON OFF and INT EXT controls operate on the function currently active for data entry This may be specified e g FM M1 AM XM or implied e g FM 1 5 KZ IM but it is recommended that the function is specified within the string to ensure that the string will always have the same result Selection of a second function via the GPIB will result in a display of the SF number being shown in the instruments modulation window Talking function 58 On receipt of the QU command the curren
52. rom 20 Hz to 50 kHz relative to 1 kHz at 80 depth d c coupled 10 kHz CARRIER VARIANTS At 10 kHz carrier frequency AM is usable with up to 1 kHz mod rate Less than 34 total harmonic distortion for modulation depths up to 804 at 1 kHz modulating frequency for carrier frequencies up to 400 MHz Less than 24 total harmonic distortion for modulation depths up to 90 at 1 kHz modulating frequency for carrier frequencies up to 32 MHz AVIONICS VARIANTS lt 0 0454 a m difference in depth of modulation for ILS tones at 90 Hz and 150 Hz each at 40 modulation depth Chap 1 Page 9 Characteristic External modulation input Pulse modulation 20 Carrier pulse response Carrier on off ratio Propagation delay pulse input to carrier pulse Input Selection and display AF oscillator 21 Frequencies Display Frequency accuracy Internal AF OSC output Chap l Page 10 H 52018 910P Vol 1 Performance With the modulation aelece on the modulation depth is calibrated for input levels between 0 8 V and 1 2 V ped With the modulation a sl c off the modulation depth is calibrated for an input level of 1 V pede HI or LO l e d s are provided as an aid to maintain calibrated modulation in the a l c off mode Input impedance is nominally 100 KR d c coupled PULSE MOD VARIANTS Rise time lt 100 ns Fall time lt 100 ns gt 65 dB at 70 MHz carrier frequency reducing to gt 50 dB
53. sequent changes from INT and EXT when the instrument is at or near normal operating temperature can be made without this delay 5 VOLTAGE SELECTOR switches selects in a combination of four positions 105 110 V 115 120 V or 210 220 V 230 240 V each has a 10 tolerance to afford a complete cover over the voltage ranges 95 V 132 V and 190 V 264 V respectively 6 Selector switch plate Secures the VOLTAGE SELECTOR switches into one of four pre selected positions by either turning and or reversing the plate before re affixing to the rear panel 7 AC fuses Supply input fuses are rated at 0 5 amp slow blow for 190 V 264 V range or 1 amp slow blow for the 95 V 132 V range 8 AC supply input The a C supply is connected through this plug which mates with the connector fitted to the supply lead C 230 240 V Moo IN 0 5 A T AN O GPIB O SH1 AH T6 L1 SR1 RL1 E1 DC RF OUT 7 POWER SUPPLY PULSE MOD O IN 105 120 or 210 240 STD FREQ o gN 50 400Hz J 85 VA AUXILIARY CONTROL O P O TPC 45C1C Fig 2 Rear panel controls with optional GPIB interface PREPARATION FOR USE Switching on 4 With the instrument connected to a suitable a c supply proceed as follows 1 Switch SUPPLY ON and check that the instrument has taken up the correct initial operating mode that is CARRIER FREQ 520 MHz 1040 MHz for 2019A internal MOD OSC 1 kHz n
54. ss at power on and on receipt of a device clear message The current GPIB address is shown in the frequency display when the interface is correctly installed GPIB programming codes 54 Functions Miscellaneous functions DE Delta Increment Decrement Cl Carrier On CF Carrier frequency CO Carrier Off FM Frequency modulation ST Store followed by a PM Phase modulation RC Recall number 00 99 AM Amplitude modulation RT Return PU Pulse modulation if option is fitted UP Increment up LV RF level DN Increment down AL Audio output level HO Set triggered output mode Off IS internal Freq Std Hl Set triggered output mode On XS External Freq Std GO Trigger output QU Query send current function setting QL Query modulation input level to GPIB buffer see Talking function SF Second function see Chap 3 para 25 Notes RS Reset RPP Mod OSC ALC Units FO Mod ose freq 300 Hz MZ Megahertz Fl Mod ose freq 400 Hz KZ Kilohertz F2 Mod ose freq 500 Hz HZ Hertz F3 Mod ose freq 1 kHz PC Percentage F4 Mod ose freq 3 kHz VL Volt F5 Mod ose freq 6 kHz MV Millivolt Ml Modulation On UV Microvolt MO Modulation Off DB Decibel IM Internal modulation RD Radians XM External modulation Al Audio output On AO Audio output Off LI Mod ALC On LO Mod ALC Off Chap 3 Jun 84 Page 2 H 52018 910P Vol lL Listening function 55 The 2018A is remotely controlled over the GPIB by strings of two character codes and digits sent in uppe
55. t running hours accumulated since the facility was last set to zero The elapsed time is shown in the Frequency display in hours with a resolution of 0 5 hrs and is not updated while being viewed After switch on the timer is updated by 0 25 hrs after 7 5 min of operation to avoid rounding errors and thereafter at 15 minute intervals The purpose of this display is to allow calculation of calibration intervals or similar periodicittes Reset to zero can be achieved by first unlocking the instrument to the second level of operation then selecting SECOND FUNCTION 9 followed by O and STORE keys Details of the unlocking procedure are restricted to the Service Manual Vol 2 A further elapsed time display second function 10 Read total instrument running hours can also be accessed after unlocking to second level of operation No means of reset is available for this display BO se Le Ly 34 Selection of this facility enables the user to confirm the Type aumber Second function il Read identity string Serial number and Software issue number of the instrument This is indicated with two separate displays the first display shows type and software issue number The second half of the string indicating the instrument serial number is displayed when the decimal point key is pressed Both displays are shown in Fig 6 below G CARRIER FREQUENCY MODULATION LEVEL an SOFTWARE ISSUE NO cae Oe mr KENT P al us TYP
56. t function setting e g CF FM is transferred to the GPIB output buffer in a format corresponding to the GPIB commands needed to set the instrument to the current state RF level will be displayed in log or linear units but without a specific reference since this information cannot be re entered directly Increment settings are also available if QU is sent whilst in DELTA mode with a current function l e d lit The following tables give the format for each type of string TABLE 1 MODULATION STRING 18 characters NUMBER OF CHARACTERS IN FIELD 3 digits or leading Spaces plus decimal point or space Represents a space which is used when the field has no relevance such as the levelling field when internal modulation is selected e g DE FM 1 00 KZ M1 IM or FM 1 23 KZ M1 IM F2 Chap 5 Page 2 Jun 84 H 5S201L3 910P Vol 1 TABLE 2 FREQUENCY STRING 17 characters NUMBER OF CHARACTERS IN FIELD e 8 digits or leading MZ S spaces plus decimal point or space a ee e g CF 123 456 78 MZ I5 KZ ae eee AD TOES IE PIE ER Mee AEN CT TS EET AED TD TABLE 3 LEVELS STRING 14 characters NUMBER OF CHARACTERS IN FIELD ms 7 a O 1 3 digits or 0 leading spaces plus decimal point Or space ED aE A O PD ED OS Ae 0 SANA ATED AY NE AEE EN EY EY CE ED SND FETC TER Om e g LV 1 000 VL Cl 59 Provision for talking second function values can also be made by a sim
57. the total deviation to il kHz If d m is selected the total number of radians will be changed in a similar manner Setting a m CJ E l4 Again the procedure for selecting a value of a m depth is similar to that described for setting f m the only differences being that the AM function key is pressed and the instruction data is ended by the 4 terminating key Setting r f level ee ed RF LEVEL 15 Press the RF LEVEL key and enter the required data including any decimal point or minus sign as required The terminator keys give a choice of volts millivolts microvolts or decibels Linear voltage scales can be calibrated in either e m f or ped and are set up by a second function control Further references for the logarithmic dB scales are also set up by the second function control for details see Second function operations An ref level displayed in logarithmic units can be converted to linear units by pressing V mV or uV keys with the RF LEVEL 1l e d lit if no data is entered The reverse operation can be carried out under the same conditions by pressing the dB key Setting pulse modulation AM I C PULSE eS a 16 The above keys are only fitted if the Pulse modulation option is fitted to the instrument To select pulse modulation press both keys simultaneously Pulse modulation is indicated by a P in the modulation display Chap 3 Jun 84 Page 9 H 52018 910P Vol 1 On O
58. ting the service required type or model number on rear label serial number and your return address Pack the instrument in accordance with the general instructions below or with the more detailed information in the packing instruction note Jus 1 Place supply lead in suitable plastic bag and tape it to the instrument rear panel 2 Place the instrument within its plastic cover 3 Ensure that the padded fitting is in place within the inner carton and slide the instrument in rear panel first leaving the front panel exposed at the open end 4 Fit the separate front panel protecting cover over the panel and close and seal the inner carton 5 Place one of the moulded plastic cushions in the bottom of the outer carton and insert the inner carton to locate in the cushion recess 6 Place the other plastic cushion over the other end of the inner carton and close and seal the outer carton 7 Wrap the container in waterproof paper and secure with adhesive tape Chap 2 84 Page 1 H 52018 910P Vol 1 8 Mark the package FRAGILE to encourage careful handling Note eee If the original container or materials are not available use a strong double wall carton packed with a 7 to 10 cm layer of shock absorbing material around all sides of the instrument to hold it firmly Protect the front panel controls with a plywood or cardboard load spreader if the rear panel has guard plates or other projections a rear load sprea
59. trument assumes operation into 50 2 external loads but often it is desirable to work into mismatched loads This is in general possible although an uncertainty of performance may be introduced When external loads of 75 2 are employed these can be accurately matched for carrier frequencies up to 500 MHz by using a 50 75 2 Impedance Adapter Code No 54411 051X offered as an optional accessory This 25 Q series load maintains the correct open circuit voltage calibration and allows the reverse power protection circuit to function correctly GENERAL PURPOSE INTERFACE BUS GPIB FUNCTIONS 43 The GPI8 interface offered as an optional accessory allows the instrument to be coupled to a controller The essential purpose of the GPIB functions are described below Further information on the general features and applications of the GPIB system can be obtained from the separate GPIB manual offered as an optional accessory 44 2018A 2019A have both talker and listener capabilities One address is used for both talking and listening and is set via the front panel or via the GPIB using Second function 2 The instrument can request service assert SKQ on certain error conditions under the control of an SRQ mask which is set using Second function 4 Chap 3 Oct 84 Am 1 Page 19 H 52018 910P Vol 1 45 SHI Source handshake complete capability The source handshake sequences the transmission of each data byte from the instrument over the bus data l
60. uch devices is also indicated in the equipment by orange discs flags or labels bearing the same symbol Certain handling precautions must be observed to prevent these components being permanently damaged by static charges or fast surges 1 If a printed board containing static sensitive components as indicated by a warning disc or flag is removed it must be temporarily Stored in a conductive plastic bag 2 If a static sensitive component is to be removed or replaced the following anti static equipment must be used A work bench with an earthed conductive surface Metallic tools earthed either permanently or by repeated discharges A low voltage earthed soldering iron An earthed wrist strap and a conductive earthed seat cover for the operator whose outer clothing must not be of man made fibre 3 As a general precaution avoid touching the leads of a static Sensitive component When handling a new one leave it in its conducting mount until it is required for use 4 If using a freezer aerosol in fault findings take care not to Spray programmable ICs as this may affect their contents CAUTION LCD HANDLING When operating or servicing this equipment take care not to depress the front or rear faces of the display module as this may damage the liquid crystal display elements WARNING HANDLING HAZARDS This equipment is formed from metal pressings and although every endeavour has been made to remove sharp points an
61. umbers 17 to 24 i e the right most bit set on page 1 indicates no response to error 1 the second from right no response to error 2 etc The modulation display gives an indication of the page currently selected 69 The mask is displayed by selection of second function 4 and may be changed by entering 17s and 0 s via the keyboard The store key is pressed to finalize a change The SRQ mask is not stored either in the instrument setting stores or when power is removed when the instrument is initially Switched on the mask is set to all O s Reverse power protection 70 When tripped by an overload applied to the RF OUTPUT socket the GPIB SRQ line is asserted and the status byte obtainable by the controller conducting a serial poll will contain the value 65 decimal The RPP can be reset via the bus by sending the RS command Chap 3 Jun 84 Page 25 H 52018 910P Vol 1 Clear switch on and return to local 71 SDC and DCL clear 2013A to the following state Max carrier freq 520 MHz 2019A 1040 MHz Min output level 127 dBm or the equivalent Carrier on FM aem pulse modulation off Internal modulation selected Increment settings Carrier freq 1 kHz FM mod 1 kHz M 1 Rad AM 14 RF level 1 dB or AF level 1 dB To revert From GPIB to front panel control press the RETURN key If a Local lock out command has been given the return key operation will be ignored NotesS eee 1 Int Ext
62. ven in para 25 select SECOND FUNCT mode and press the numerals 16 Then press the 1 key to select automatic recall of STORE 10 Finally press the STORE key If the supply voltage is interrupted then restored the instrument will first reset to the initial operating mode then automatically carry out a RECALL 10 instruction and reset to the STORE 10 conditions previously set To disable the facility first unlock the instrument to First level operation select SECOND FUNCT 16 followed by the numeral 0 and finally the STORE key mja ENEE AEE i aE ae ee FEE erae aee EEE S ee a ae rae i ead E eee ea E e a 40 In addition to allowing full GPIB control of the Signal Generator the GPIB module AGO has an auxiliary output socket which can be used to control external relays or similar This 14 pin plug fitted on the rear panel GPIB interface can easily be accessed by removing a plastic cover Data is set to control the eight external data lines after selecting second function 18 Connections from the Auxiliary output are best made using an IDC ribbon cable connector provided with the Optional GPIB interface kit Interconnections and operation is as follows 1 Plug PLDW pin 5 may be keyed to prevent incorrect insertion of the IDC connector Pin connections as seen from the rear panel are shown below PLDW 14 13 12 11 70 9 8 Po St al A l oF IC9b 2 74S 20 Fig 7 GPIB auxil
63. xiliary output facility Table Page l Modulation string GPIB eee tes eas oes eos eee 22 2 Frequency string GPIB aoe eee eae ea eee eos 23 3 Levels string GPIB ese ese eee eas eee eco 23 Fig L Front panel controls eee eee eee e o s o coe 3 2 Rear panel controls e eso s o s coe eee coe 4 3 2018A Initial operating mode eee ene coe s o ss 5 4 2018A Second function 1 status mode o o eae coe eee L3 p SRQ mask setting display cee cee cee t o s eos l4 6 Read Identity display eee eee coe bee cee eee LO 7 GPIB auxiliary output plug and socket connections eo eee 18 8 GPIB connector contact assignments oes cee cee eee 2 9 2018A 2019A Simplified Block Diagram ene coe s eee 28 29 PRINCIPLES OF CONTROL l All operations of the generator are carried out from the front panel Keyboard which is divided into five distinct areas Remote operation via a GPIB controller is possible if the optional GPIB interface is fitted If an illegal operating condition is selected either by local or remote control this is indicated by a limit annunciator on the front panel display 2e 1 SUPPLY switch Applies the a c supply voltage 2 AF OSC MOD ALC The two black keys control the internal modulation frequency and the modulation automatic level control The MOD ALC key has an integral l e ed to indicate that selection has been made When MOD ALC is selected a MOD input of between 0 8 1 2 V will be automatically levelled
64. xternal and the EXT annunciator will set in the modulation display window Pressing the INT EXT key again will return the f m to the internal mode MOD ON OFF 2 To turn f m off whilst still retaining the current value of entered deviation press MOD ON OFF key The off condition is indicated by the setting of an OFF annunciator in the modulation display window Entering a new value of f m deviation will automatically select the f m on again O e E Ee 3 If the 2018A is to be utilized for signal to noise measurements within a narrow bandwidth a useful reduction of residual noise level may be obtained from the instrument at frequencies adjacent to the carrier frequency This can be achieved by the selection of FM and a setting of 0 deviation A useful alternative method for controlling the FM deviation setting if required is to use the DOWN key to reduce the value to zero and the RETURN key to return to a previous setting Setting m 12 fe rad dB The procedure for selecting a value of phase modulation is the same as for f m with the RAD key terminating the entry Chap 3 Page 8 Jun 84 H 52018 910P Vol il Auxiliary f m input socket 13 Applying a 1 V r m s signal to the AUX FM INPUT socket enables the value of the displayed f m to be increased by 104 of the same numerical deviation g indicated deviation of 10 kHz auxiliary f m of 1 kHz increases
65. y Two l ee d indicators HI and LO provide an aid to maintain calibrated modulation in the ael cse off mode ALC ON Input level nominally 1 V r m s into 100 kR see under Frequency modulation and Amplitude modula tion ALC OFF 1 V r emes is required for cali brated conditions When the HI and LO l e d s are extinguished the input voltage will be within the range 1 V 524 The auxiliary FM input can be used to add sub audio tones to the main modulation sete The input is enabled whenever FM or M is selected and is independent of whether the instrument is set to internal or external modulation With the FM on INT or EXT the application of 1 V r m s to the AUX FM INPUT will result in an f m deviation of 10 of that indicated in the modulation display With o m selected INT or EXT the application of 1 V r em s will result in an f m deviation in kHz equal to the phase deviation in radians shown in the modulation display 155 600 Q This facility is intended to allow the insertion of signalling tones used in receiver testing Jun 84 Characteristic Frequency standard input output Internal standard output External standard input Alternative RF and modulation sockets Keyboard and displays 24 Main and secondary keyboard functions Displays Jun 84 H 52018 910P Vol 1 Performance A rear panel BNC socket provides an output from the internal frequency standard whe

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