User Manual - SignalHound
Contents
1. 14 3 1 4 Measuring Low Level Signals 15 8 2 8 3 8 4 Measuring Receive 77 31 8 5 Inputs 1 8 6 ENVIrONMENL 31 8 7 Calibration 32 8 8 32 8 9 Optional 32 9 REVISION HISTORY 33 10 WARRANTY AND DISCLAIMER 34 10 1 1 Warranty 10 1 2 Warranty Service 34 10 1 3 Limitation of 34 10 1 4 Exclusive Remedies el 10 1 5 Certification 10 1 6 Credit 1 0110 PREPARING FOR USE 1 Preparing For Use Unpacking your Signal Hound and Installing Software spectrum analyzer and measuring receiver with an RF preamplifier Using recent innovations in RF technology the Signal Hound has the sensitivity accuracy and dynamic range you d expect in a unit many times its cost The Signal Hound is powered from the USB cable eliminating the need for a separate power supply Measuring less than 8 inches long and weighing only ten ounces the Signal Hound can be used virtually anywhere he The Signal Hound USB SA44B is a USB based 1 Hz to 4 4 GHz economy 44 1Hz to 4 4GHz Analyzer Measuring Receiver signal Hound MADE IN USA Patent Pending www SignalHound com 1 1 Initial Inspection Check yo2. IF Bandwidth may be set from 30 KHz to 240 KHz FM De emphasis is a digital single pole low pass filter used to remove the high frequency emphasis used in many FM broadcasts or to filter out noise Apply Changes stops the demodulation applies any new settings then re starts the audio 4 1 4 Using an External Timebase An external 10 MHz timebase my be used to improve the accuracy of frequency and phase noise measurements The level of the external timebase must be gt 0 dBm 13 dBm is recommended to achieve optimal phase noise performance To use simply connect the timebase to the Ext Ref In after connecting the USB launch the software then select Utilities gt External Reference 4 1 5 Using an External Trigger TTL CMOS trigger may be used to initiate a sweep at a specific time The trigger must be 3 3V 5V TTL CMOS To activate select Settings IN The selected sweep will wait for a trigger then begin within 10 microseconds of the trigget s rising edge When using an external trigger remember that image rejection happens in a separate sweep after the first sweep is triggered so turn it off if it will interfere If you are trying to capture an event you may wish to use Zero Span AM or FM 22 ADDITIONAL FEATURES 4 1 6 Using Sync Out 3 3V CMOS output may be used to trigger external equipment The Sync Out goes high as each sweep begins and remains high until the swee
3. Fine tune a marker s placement using your mouse wheel GETTING STARTED PEAK moves the marker to the highest amplitude signal on the graticule DELTA anchors the marker s reference e g 1R at the marker s current position Move the marker by left clicking and or using the mouse wheel to make differential measurements relative to the reference UPDATE ON OFF When Update is ON the marker s amplitude updates each sweep When OFF the marker s amplitude does not update unless it is moved WD T q OFF PEAK DELTA is good for reliable dBc OFF turns the marker off and back to default measurements settings gt to CF sets CENTER FREQUENCY to the current marker position gt MKR to REF LVL sets the REFERENCE LEVEL to the current marker position 2 2 5 BANDWIDTH CONTROLS gt Res BW This controls the resolution bandwidth RBW For each span a range of resolution bandwidths may be used The resolution bandwidth controls the Intermediate Frequency IF bandpass filter Resolution bandwidths are available from 0 1 Hz to 250 KHz typically in powers of 2 A 5 MHz RBW is also available for limited functions o The SPAN stop start frequencies will affect which RBWs are available o The SPAN and RBW determine the number of data points in a sweep roughly 2 5 x SPAN RBW Video BW This controls the video bandwidth VBW After the signal has been passed through the RBW filter i
4. AM modulation envelope after IF and audio filtering The units for all AM readings are percent 3 7 Limitations of the Signal Hound 3 7 1 RBW Limitations Although a resolution bandwidth RBW of 0 1 Hz is available for very narrow spans be aware of the limitations The internal timebase has phase noise limiting the usefulness of narrow RBWs For best results keep your RBW in Hz larger than your CENTER FREQ in GHz when using the internal timebase For example for a 1 6 GHz CF use an RBW of 1 6 Hz or higher Your RBW may be 10x less when using a high quality external timebase The Signal Hound mostly uses digital RBWs in powers of two starting at 0 1 Hz 3 7 2 IF Feed Through Intermediate frequencies of 2 9 MHz and 10 7 MHz are used for all frequencies An RF input signal near these frequencies may generate spurious responses and degrade the performance of the image rejection algorithm 3 7 3 LO Leakage A Local Oscillator signal may be observed at the RF input port often found 10 7 MHz above the RF frequency being scanned Typically this level will not interfere with your measurements If you are connecting to an antenna please use the preamplifier and set the attenuator to 15 dB to minimize LO leakage This will typically reduce your LO leakage to less than 2 nanowatts for all frequencies below 1 GHz 3 7 4 Sweep Time Sweep Time varies based on system settings For sweeps with a small span typically less than 5 MHz the user may
5. but it is typically within 20 26 TROUBLESHOOTING 6 Troubleshooting If you experience a problem with your Signal Hound please try these troubleshooting techniques before contacting us 1 Your Signal Hound Is Not Sweeping Properly gt Try this first Close the Signal Hound software Unplug the USB cable and any external 10 MHz or trigger cables from the Signal Hound and wait 15 30 seconds Plug the USB cable back in Check that both ends of the USB cable ate firmly seated and the Signal Hound LED is green Launch the Signal Hound Software Try your sweep again gt Still not working Unplug the USB cable from the Signal Hound Disconnect all USB devices from your PC Reboot your PC Wait until the PC has completed rebooting Plug in the Signal Hound s USB Launch the Signal Hound Software Try your sweep again gt Still not working Contact technical support at http www signalhound com 2 Your Signal Hound LED is off gt Make sure the USB cable is connected at both ends your PC is on and the USB drivers are installed properly gt Is your or laptop configured in low power mode The Signal Hound is a high powered USB device and may be shut down in some power saving configurations 3 Your Signal Hound doesn t find a signal gt Is it a swept or transient signal a pulse or a rapidly modulated signal If so and you know the frequency of the signal set up for a 200 KHz span or less then turn
6. external External Trigger 3 3V CMOS TTL input 8 4 Measuring Receiver FM Accuracy 1 typical AM Accuracy 1 typical Synchronous Level Detector 15 KHz IF BW timebases locked 100 KHz to 1 GHz 0 dBm to 125 dBm after 10 min warmup 0 25dB 1 GHz to 4 4 GHz 0 dBm to 115 dBm after 10 min warmup 0 25dB Average Level Detector 15 KHz IF BW 100 KHz to 4 4 GHz 0 dBm to 70 dBm after 10 min warmup 0 25dB Maximum IF Bandwidth 240 KHz Audio Filters Low Pass Digital Windowed Sinc selectable cutoff Band Pass Selectable center frequency narrow band recursive 160 Hz 3 dB bandwidth Maximum sample rate 486K sec 8 5 Inputs and Outputs 1 BNC External Timebase 10 MHz input 2 BNC Shared Self Test Output o SYNC Out Sweep Trigger In 3 SMA RF Input 8 6 Environment Operating Temperature 0 to 70 C std 40 to 85 C option 1 31 SPECIFICATIONS 8 7 Calibration Test with factory calibration software to verify that USB SA44B is operating within tolerance Recommended calibration interval is 1 year at 20 C to 25 C 8 8 Adjustments Factory adjustment software shall be used to generate new calibration constants when USB SA44B will not pass calibration Temperature correction data is generated only at time of manufacture 8 9 Optional Accessories 1 2082 Fixed Attenuator Mini Circuits Part VAT 20 2 DC Block Mini Circuits Part BLK 89 3 SMA m to BNC f Adapter Mini Circuits SM BF50 4 3GH
7. image suppression off This disables the image rejection algorithm which will reject data if it has moved or disappeared when the image is checked it also allows the image frequency through which is 21 4 MHz above the CENTER FREQ You may also try MAX HOLD to capture transient signals 27 TROUBLESHOOTING 4 Your phase noise seems too high You may consider using a low phase noise external reference or contacting us about lower phase noise options Be aware that the Signal Hound phase noise is noticably higher than a YIG based spectrum analyzer especially at higher frequencies 5 You receive a specific error code Error 1 Your Signal hound was not found on a USB port Plug in your Signal Hound if it isn t already If it is already plugged in unplug it reboot re install the USB driver and or try a different USB port Error 2 6 A USB communications error occurred If multiple errors occur close out of the software unplug the Signal Hound wait 20 seconds plug it back in and try again If you get a recurring error please make a note of the error number and e mail or call tech support 6 General Advice to avoid problems gt Unplug your Signal Hound from the USB port when not in use or before shutting down your computer Do not connect your Signal Hound s USB port until your computer has completed its bootup sequence If you do it may need to be unplugged for 20 seconds then plugged back in before operating proper
8. is available to quickly plot SSB phase noise from 1 Hz to 1 MHz For best results it is recommended to use this utility with a high quality OCXO external timebase of 13 dBm input with External Reference selected To use the utility center your CW signal on the graticule with a span of 1 KHz or less If the frequency is known and timebases locked simply enter the frequency as the CENTER FREQ Then select Utilities gt Phase Noise Plot Your span must be 10 KHz or less to invoke this utility and the amplitude of the aws signal must be 0 10 dB q below the reference level The automated phase noise measurement takes several seconds or longer depending on settings Video Averaging may be enabled to smooth our any bumps in the signal Set to Video Averaging to 10 to reduce the uncertainty in your measurement Figure 2 Phase Noise Plot 17 TAKING MEASUREMENTS The Signal Hound s internal TCXO timebase contributes more phase noise to these measurements than an external OCXO 10MHz timebase Please review the Signal Hound s specifications for phase noise If the signal you re measuring has considerably more phase noise than the Signal Hound you should be able to get meaningful results using the internal TCXO timebase Otherwise an external OCXO timebase will be needed to make a useful measurement When your measurements complete again select Utilities Phase Noise Plot to un che
9. off for large signals above 20 dBm with attenuator at 0 dB Preferences Store user Preset Settings Saves current state as the preset state The Signal Hound will enter this state when the software is launched Restore Factory Preset Restores the original preset state Ref Level Offset Adjusts the displayed amplitude to compensate for an attenuator probe or preamplifier Set Marker Freq Places the active marker at a specific frequency Signal Track At the end of each sweep the center frequency will be set to the frequency of the peak signal thus tracking the peak signal SYNC TRIG Used to enable an external trigger or to generate a sync signal when a sweep begins Generally used in Zero Span Video Averaging Averages several sweeps together and shows the result UTILITIES gt gt Measuring Receiver This invokes the Measuring Receiver software See the Measuring Receiver section of the manual for details Harmonics Plot This plots the fundamental through the 5th harmonic single plot by taking the current center frequency or marker and capturing trace data at each multiple of the frequency Phase Noise Plot This utility takes about 1 minute to run It will sweep several times then combine the sweeps into a phase noise plot The data is approximate and is limited by the phase noise of the Signal Hound itself For best close in phase noise use an external 10 MHz reference with g
10. operate with up to 0 dBm input but keeping the input level 25 dBm lower will greatly improve linearity 5 1 3 IF to Bits Receiver The IF to bits receiver has three gain ranges and several selectable bit rates The gain range will be automatically selected based on attenuator settings and reference level to avoid IF ADC compression which will greatly distort the data The software should watn you if compression is occurring If this happens change reference level attenuator and or input level settings 5 1 4 IF and RBW Selection The I Q data comes in over USB and is processed using an FFT with a Flat Top window The software controls the bit rates and the size of the FFT based on your selected RBW The available RBWs are a function of the span since very large RBWs with a small span would result in a trace with only a few data points and a blocky appearance and very small RBWs with a large span would result in a large data set that would be difficult to manage and process The resolution bandwidths are not the traditional analog 1 3 10 KHz filters The bandwidths are a function of the size of the FFT which is a power of 2 The RBW listed on the GUI is calculated from the bit rate divisor and FFT size This number is the approximate RBW and is listed in the lower left region of the GUI For 25 THEORY OF OPERATION wide spans an additional RBW of 5 MHz is used This is a typical value There is no specification for this RBW
11. select slow medium or fast sweep speeds depending on the application Except for zero span sweeps the user does not get to explicitly specify sweep time 20 ADDITIONAL FEATURES 4 Additional Features Learn about save recall state Automation Live Audio Streaming and Printing making printing and automation easy and straightforward Saving and recalling instrument states are now as simple as saving and opening files with virtually no limit to the number of instrument states saved Each instrument state saves into approximately 1 5 MB on your hard drive making it possible to save thousands of captures Since most Windows PCs come with speakers as well demodulated audio can even be played in real time through the computer speakers he Signal Hound leverages the power and flexibility of your Windows PC 4 1 1 Recall State To save an instrument state including trace data attenuator settings frequency settings and more select File gt Save State from the menu A standard File Dialog box will open prompting you to supply a filename This may be any legal file name and may be stored to any File Folder under Windows However for simplicity it is often best to save states in the default folder It is recommended when saving a trace capture to press SWEEP SINGLE then wait for the trace to complete before saving That way the state recalled has the trace captured and the sweep paused To recall a p
12. shall pay UPS Ground or equivalent shipping charges to return the product to the Buyer However the Buyer shall pay all shipping charges duties and taxes to and from Test Equipment Plus for products returned from another country 10 1 3 Limitation of Warranty The foregoing warranty shall not apply to defects resulting from improper use by the Buyer Buyer supplied software or interfacing unauthorized modification or misuse Operation outside of the environmental specifications for the product No other warranty is expressed or implied Test Equipment Plus specifically disclaims the implied warranties or merchantability and fitness for a particular purpose 34 10 1 4 Exclusive Remedies The remedies provided herein are the Buyer s sole and exclusive remedies Test Equipment Plus shall not be liable for any direct indirect special incidental or consequential damages whether based on contract tort or any other legal theory 10 1 5 Certification Test Equipment Plus certifies that at the time of shipment this product conformed to its published specifications 10 1 6 Credit Notice Windows is a registered trademark of Microsoft Corporation in the United States and other countries 35
13. this box will zero the relative power reading and enable the average detector Use this to measure a noisy modulated or drifting signal over a 80 90 dB dynamic range Show FM Check this box to view FM modulation measurements Show AM Check this box to view AM modulation measurements 3 6 2 The Analyzer Data Window RF COUNTER displays the carrier frequency It has 1 100 Hz resolution but its accuracy may be lower than this at high frequencies or IF bandwidths gt FM Modulation Readings are readings taken on the FM modulation after IF and audio filtering The units for all FM readings are Hz o RMS This is the root mean square of the FM modulation sometimes referred to as the average FM deviation RMS With single tone modulation this is equal to the FM Peak ot Peak with noise spikes smoothed PEAK This is the highest instantaneous frequency above the carrier 19 TAKING MEASUREMENTS PEAK This is the highest instantaneous frequency below the carrier o Audio Freq This is the count of the demodulated audio frequency Relative Power is the change in power reported from the Synchronous Average power detector The reference power level 0 dBc is set to the power when the START button was first pressed It may be reset to 0 dBc by checking or un checking the Synchronous Level Detector box o Averaged is the average of the last ten relative power readings AM Modulation readings are taken on the
14. Feed Through 20 2 2 2 SPAN 5 3 73 LO Leakage 20 2 2 3 AMPLITUDE CONTROLS 3 7 4 Sweep 20 2 2 4 MARKER CONTROLS 2 2 5 BANDWIDTH CONTROLS eae TRACE CONTROLS 4 ADDITIONAL 21 2 2 7 TRIGGER AND SWEEP CONTROLS 8 411 Save Recall State 21 2 2 8 ADDITIONAL CONTROLS 9 412 Printing 4 1 3 Listening to Demodulated Audio 22 2 3 0 9 4 1 4 Using an External 110160886 22 2 3 1 FILE 9 4 1 5 Using External Trigger 22 EDIT wd 4 1 6 Using Sync 2 3 3 VIEW 9 2 3 4 SETTINGS 9 2 3 5 UTILITIES 10 5 THEORY OF OPERATION wen 24 2 3 6 TRACE 514 The Four Sweep 24 2 3 7 7 5 1 2 Reducing Spurious and Residual 2 3 8 5 1 3 IF to Bits Receiver 2 and RBW Selection 25 5 14 12 dhe Siena Bowne E ronk S ear Panels vals 6 27 3 20 TAKING MEASUREMENTS 13 7 CALIBRATION AND ADJUSTMENT Sales 29 3 Measuring Frequency and Amplitude 13 3 1 3 1 1 Using the Markers cesses 13 8 30 3 1 2 Example Identify a Signal s Frequency and Amplitude 14 81 30 3 1 3 Using the DELTA
15. TEST EQUIPMENT PLUS Signal Hound USB SA44B TEST EQUIPMENT PLUS Signal Hound USB SA44B User Manual 2010 Test Equipment Plus 35707 NE 86 Ave Phone 360 263 5006 Fax 360 263 5007 Version 2 05A Table of Contents 3 1 5 Measurements Near DANL 15 3 1 6 Capturing Pulsed or Intermittent Signals 15 1 PREPARING FOR 1 3 2 Viewing Modullation cssssssssssssssesssesseeee 15 11 Initial 1 3 2 1 Capturing Pulses in Zero 16 12 Software Installation sssssssssssssesssesssseseee 2 3 3 Understanding Your Signal Hound 16 1 2 1 System 2 122 Install the Signal Hound Software 2 3 4 Measuring Harmonics 17 13 Running the software for the first time 2 3 5 Measuring Phase 17 2 GETTING 4 3 6 Using the Measuring Receiver Utility 18 3 6 1 Audio Analysis Controls 18 3 6 2 The Analyzer Data 19 2 1 4 3 7 Limitations of the Signal Hound 20 2 2 Control 371 RBW Limitations 20 2 2 1 FREQUENCY CONTROLS 372 IF
16. You must reboot your PC before the Signal Hound will operate correctly 1 3 Running the software for the first time 1 Using the included USB cable connect the Signal Hound to any available USB 2 0 port Wait while Windows installs the necessary device drivers This takes several seconds Once you see The hardware is ready to use continue 2 Launch the Signal Hound application from the Start Menu or desktop The first time the software runs temperature corrections are downloaded from the internet and calibration data is transferred from the Signal Hound to the computer This takes about 10 seconds 3 You may begin using the Signal The Signal RF Hound Spectrum Analyzer now If you A input is DC coupled _ Always use DC block wish to optionally verify basic when your signal has AC functionality proceed with the next steps and DC combined 4 Connect the SELF TEST BNC PREPARING FOR USE output to the RF IN SMA input using a BNC cable and BNC to SMA adapter 5 From the GUI select Utilities SELF TEST 6 Observe that all self tests pass If not see the Troubleshooting section GETTING STARTED Ci 2 Getting Started Learn about the basic functions and features of your Signal Hound Spectrum Analyzer and Measuring Receiver The Signal Hound Graphical User Interface or GUI is used to communicate with the Signal Hound sending commands and receiving data over USB The user sends commands
17. and one below These are masked together to produce the displayed trace LO and IF frequencies selected automatically to best cancel image and spurious responses 24 THEORY OF OPERATION gt Spans using 6 5 KHz 250 KHz RBW VBW the Signal Hound operates by rapidly stepping LO frequencies in 200 KHz steps covering above and below the center frequency These are processed with small FFTs and masked together to reject image responses and produce the displayed trace For RF frequencies below 25 MHz image rejection requires additional steps and the trace will be slower gt 5 MHz RBW This feature is coming soon Rapidly sweeps across the spectrum to find a strong signal quickly Certain RF frequencies may produce spurious responses in this mode and amplitude accuracy is not guaranteed 5 1 2 Reducing Spurious and Residual Responses Certain RF frequencies may produce small spurious and or residual responses To verify a displayed signal center it and step the span down to 10 KHz or less If it disappears it was likely a mixing artifact or a harmonic from a system clock To avoid known residual responses at multiples of the primary system clocks a secondary clock frequency is selected for spans 100 KHz or below Measurement tip Linearity p of a mixer improves at lower signal levels For accurate harmonics measurements you should have less than 25 dBm into the mixer The mixers can typically
18. ar automatically displays the frequency or time of the mouse s x coordinate and the signal level of the trace at that frequency or time This can be used to check a signal level without moving the markers It can also be used to help you more accurately place markers position on the graticule 2 5 The Signal Hound Front amp Rear Panels The front panel includes a 50Q SMA RF input Do not exceed 20 dBm or damage may occur A READY BUSY LED flashes orange each time a command from the computer is processed Reapy INPUT 500 BUSY 62 The rear panel has three connectors 1 10 MHz Reference input automatically detected after each sweep completes Use a I N clean 10 MHz reference with 20 dBm level 5 13 dBm is recommended Mex ee 2 A USB type B connector Connect to your PC using the included USB cable 3 A multi purpose BNC connector This may be used as TTL CMOS trigger input a Self Test Signal output a Tracking Generator Sync signal or a generic CMOS Sync Output The Signal Hound software controls the function of this BNC It defaults to unused no output 12 TAKING MEASUREMENTS 3 Taking Measurements Learn how to take amplitude frequency and modulation measurements with the Signal Hound internal I Q demodulator captures up to 2 Megabytes of information each second with a hardware limited bandwidth of 250 KHz The trace is actually a com
19. bination of several sweeps mathematically combined to reject image and spurious responses When taking measurements of highly modulated signals which exceed this 250 KHz bandwidth or any combination of signals with a bandwidth of gt 250 KHz great care must be taken as the I Q demodulator will reject out of band responses In other rare instances multiple CW input frequencies that are not harmonically related can mix to produce spurious responses For these reasons the Signal Hound is not recommended for taking measurements of signals with a bandwidth of greater than 250 KHz T he Signal Hound is capable of making a wide range of measurements The For signals within the 250 KHz bandwidth limit a high degree of accuracy and sensitivity are available The I Q demodulator has dual 24 bit DACs yielding a very high internal resolution 3 1 Measuring Frequency and Amplitude 3 1 1 Using the Markers The Signal Hound has several tools for identifying a signal s frequency and amplitude The easiest to use is the Marker There are 9 markers available each with its own reference To activate the marker and place it at the peak frequency locate the Marker PEAK button on the Control Panel The frequency and amplitude readout of the marker is located below the graticule The marker s accuracy is dependent on the SPAN and RBW Narrower spans amp RBWs have higher marker accuracy The amplitude accuracy is NOT dependent on the vertical dB div si
20. ck this utility and resume normal operation 3 6 Using the Measuring Receiver Utility The measuring recetver utility takes measurements of AM and FM modulation and relative signal level measurements If you are familiar with other measuring receivers some of this information will be redundant In addition to modulation measurements the measuring receiver also accurately measures relative power RE Gamer Freq 27 MHz RF COUNTER 27000000 05 Hz FM RMS 357 67 Hz IF Bandwidth 60 KHZ lz RMS RT2 505 82 Hz eres PEAK 525 4 Hz Audio Filter LowPass KHz 523 3Hz Audio Freq 1002 604 Hz Synchronous Level Detector Relative Power 0 001 dBc Show FM Frequency Modulation Averaged 0 000 dBc Show AM Amplitude Modualtion Amplitude Range Select gt High Power Range To use this center the signal on the graticule in the spectrum analyzer with a span of 200 KHz or less then select Utilities gt MEAS RCVR the menu Note The carrier frequency for modulation measurements will be set to the CENTER FREQ from the spectrum analyzer EXIT Figure 3 Measuring Receiver Enter the desired IF and audio settings then click START to begin analysis 3 6 1 Audio Analysis Controls Cartier Freq the frequency of the RF carrier IF Bandwidth keep this at least 2 4x your peak FM modulation Any modulation outside this bandwidth will be rejected Audio Low Pass This selec
21. clicking inside the calculated from FFT size and sample rate graticule at the desired location gt VBW Video Bandwidth currently selected SPAN Difference between start and stop frequencies gt SWP In zero span this is the exact sweep time from left to right In all other spans this is time elapsed during the last sweep gt MARKER DATA will appear along the bottom of the graticule Annunciators In the top left corner of the graticule you may see some letters These will notify you when readings are uncalibrated or a special setting exists such as image rejection off See the HELP menu for additional information 2 2 The Control Panel The control panel is the section on the right hand side of the Graphical User Interface GUI It has buttons for the most common user commands Frequency span reference level trigger video and resolution bandwidth processing sweep and marker commands are available here Try this Click CENTER FREQ then using the mouse click the buttons 1 2 3 MHz You should see your center frequency change to 123 MHz Now click SET SPAN 5 0 KHz Watch as start and stop frequencies and span are updated in the lower section of the graticule GETTING STARTED 2 2 1 2 2 2 2 2 3 2 2 4 FREQUENCY CONTROLS CENTER FREQ sets the center frequency of the sweep When clicked a popup will open allowing you to enter the frequency using the mouse or keyboard STEP sets the
22. e note that the waveform displayed represents a sampling of spectrum above and below the frequency reported The response is uncalibrated and will yield unpredictable amplitudes for narrow band signals To resume normal operation click Broadband Signal Peaking a second time Harmonics Viewer Displays the amplitude of the first 5 harmonics of the center frequency when checked It is recommended to have a span of 200 KHz or less before starting the Harmonics Viewer To resume normal operation click Harmonics Viewer a second time to un check Phase Noise Plot Displays the phase noise amplitude in dBc Hz vs offset from carrier when checked You must have a span of 10 KHz or less and the signal should be within 1 division of the reference level e g within 10 dB To resume normal operation click Phase Noise Plot a second time to un check Self Test Requires a BNC cable and BNC to SMA adapter Loops the Self Test Output back to the RF Input through a customer supplied coax testing the basic function blocks of the spectrum analyzer HELP gt About Signal Hound Look here for hardware software and firmware versions Annunciator Help Explains the meaning of various annunciators which appear in the top left graticule User Manual Opens this manual SignalHound com Takes you to the website 11 GETTING STARTED 2 4 The Status Bar When the mouse pointer enters the graticule area the Status B
23. frequency increment decrement amount Default is 10 MHz The UP and DOWN arrows will change the center frequency by a preset STEP amount START and STOP set the sweep s start and stop frequencies respectively SPAN CONTROLS SET SPAN sets the span of the sweep the difference between start and stop frequencies The center frequency is held constant gt The UP and DOWN arrows will step through the default spans from 100 Hz to 1 GHz in a 1 2 5 pattern ZERO SPAN changes the x axis on the graticule to time instead of frequency The y axis may be demodulated amplitude or frequency When this button is clicked a popup will open allowing the user to select amplitude AM or frequency FM for the y axis FULL SPAN sets the span to its maximum AMPLITUDE CONTROLS REFERENCE LEVEL sets the power level for the top graticule line gt The and DOWN arrows will change the reference level by a preset amount equal to dB div gt ATTEN sets the internal electronic attenuator to 0 5 10 or 15 dB dB div sets the scale for the y axis It may be set to any positive value 10 dB div is default giving a full scale range of 100 dB LIN sets the amplitude scale to linear voltage units instead of logarithmic MARKER CONTROLS gt The left right arrows scroll between the available markers Markers 1 thru 9 are available each with its own reference point You may place a marker by simply clicking on the trace
24. kets of data quickly from several local oscillator frequencies For narrower spans a software controlled sweep collects large amounts of data from a smaller set of local oscillator frequencies 3 1 3 Using the DELTA Marker To measure a difference or change in frequency and or amplitude use the DELTA market 1 Select a marker 1 thru 9 from the control panel 14 TAKING MEASUREMENTS 2 Turn the marker off if it is currently on Adjust the settings until your desired signal is displayed with a span narrow enough for your required accuracy A 5 to 50 KHz span is ideal for many measurements 3 Place your marker using the mouse left click or the PEAK button 4 Press the DELTA button This freezes the location of the first market s REFERENCE point e g 1R 5 Move the marker by left clicking inside the graticule then using the mouse wheel to fine tune the market s position 6 The differential measurement is displayed below the graticule If you want the marker to update automatically with each sweep toggle UPDATE OFF to UPDATE ON 3 1 4 Measuring Low Level Signals To measure low level signals there are a few tricks to getting accurate readings First of all set the internal electronic attenuator to 0 dB click the ATTEN button Then set your reference level to 40 dBm or lower This internally selects the highest sensitivity settings Using an external timebase and narrow span 1 KHz or less should give you bet
25. layed Average Noise Level 0dB input attenuation 1Hz RBW Frequency RF Preamp Off RF Preamp On 10Hz 124 dBm NA 100Hz to 10KHz 130 dBm NA 10KHz to 500KHz 142 dBm NA 500KHz to 10MHz 142 dBm 153 dBm 10MHz to 100MHz 148 dBm 161 dBm 100MHz to 1GHz 144 dBm 158 dBm 1GHz to 2 6GHz 139 dBm 151 dBm 2 6GHz to 3 3GHz 135 dBm 151 dBm 3 3GHz to 4 4GHz 128 dBm 134 dBm Absolute Accuracy Reference level lt 0 dBm 1 5dB no warm up required Absolute Accuracy 0 dBm gt Reference level gt 10 dBm 2 0dB 30 SPECIFICATIONS Relative Accuracy Reference level 50 dBm 0 25 dB Maximum Safe Input Level preamp off 15 dB atten 20dBm DC Volts gt 0 2V absolute maximum Residual Responses Input terminated 5100 KHz span 0 dB atten lt 80 dBm Note 1 Known residual responses at multiples of 10 MHz Spurious Responses 2100 KHz span CW tone input lt 80 dBm typical Typical Maximum LO Feedthrough preamp on attenuator set to 15 dB 1Hz to 500KHz 70 dBm 500KHz to 1GHz 57 dBm 1GHz to 2 3GHz 47dBm 2 3GHz to 2 6GHz 40 dBm 2 6GHz to 3 0GHz 27 dBm 3 0GHz to 4 4GHz 35 dBm RF Preamp Off and Internal input Attenuator on any setting 8 3 Sweep Zero Span Sweep Time 0 1 ms to 10 sec 0 1 All other sweeps times are estimates reported after sweep completes Maximum sample rate 486K sec Sweep Trigger free run single video
26. ls Under many conditions it is ignored gt Image Reject Turn OFF to catch a transient signal that lasts for duration less than the sweep time Turn ON to filter out image frequencies and noise when a steady signal is present TRACE CONTROLS gt NORMAL The entire trace is updated each sweep gt MAX HOLD The highest amplitude for each frequency point is displayed Each sweep only frequency points with higher amplitudes are updated TRIGGER AND SWEEP CONTROLS CONTINUOUS A new sweep begins as soon as the last sweep 15 completed SINGLE A single sweep is run then the Signal Hound remains inactive FREE RUN In Zero Span mode a sweep begins immediately gt VIDEO In Zero Span mode the Signal Hound waits for minimum signal amplitude before sweeping When clicked a popup opens where the user sets the minimum signal amplitude This is useful for measuring pulses as short as 10 microseconds GETTING STARTED 2 2 8 ADDITIONAL CONTROLS PRESET restores the Signal Hound software and hardware to its initial power on state 2 3 The Menu 2 3 1 FILE gt Recall State This loads a previously saved instrument state including trace data It can be used to recall an instrument setup or view saved trace data States are saved as standard Windows files with the tsa extension gt Save State This saves an instrument state including controls and trace data SaveAs Same as above with a different filename Ex
27. ly Do not overpower the Signal Hound 28 CALIBRATION AND ADJUSTMENT 7 Calibration and Adjustment Contact Test Equipment Plus for more information regarding calibration software and required equipment 29 SPECIFICATIONS 8 Specifications Unless otherwise stated specifications are valid for an ambient temperature range of 0 to 70 C or 40 to 85 C for option 1 image rejection on amplitude of signal applied less than the reference level 8 1 Frequency Frequency Range 1 Hz to 4 4 GHz Span Modes Center Frequency Span or Start Stop Frequencies Maximum Span 4 4 GHz Minimum Span 10 Hz or Zero Span Internal Frequency Reference Accuracy 1 ppm For greater frequency accuracy connect to external 10 MHz timebase 0 to 20 dBm Frequency Readout Accuracy reference error 1 sample Marker Accuracy reference error 1 sample Resolution Bandwidth 0 1Hz to 250KHz and 5MHz Spectral Purity Residual FM 3KHz Audio LPF 15 KHz IF BW 0 1 Hz 4 Hz GHz typical RMS FM e g 2 GHz RF would have 8 1 Hz RMS FM Increasing IF BW increases residual FM Note 1 1 sample represents approximately 40 of the selected RBW Note 2 5 MHz RBW accuracy not specified software support coming soon 8 2 Amplitude RBW 100KHz Range 1dB Gain Compression to Displayed Average Noise Level DANL 1dB Gain Compression attenuator set to 15dB preamp off 16dBm Typical 1Hz to 150MHz 19dBm Typical 150MHz to 4 4GHz Disp
28. nce the I Q data is linear in voltage and has much higher resolution than is displayed 13 TAKING MEASUREMENTS To measure a signal that is not the peak you may simply move the mouse over the desired signal and left click to place a marker The frequency and amplitude are read as before 3 1 2 Example Identify a Signal s Frequency and Amplitude TRY THIS EXAMPLE find a signal within a certain frequency range e g 200 MHz to 500 MHz and measure its exact frequency a gt simple procedure would be 1 Set START FREQ to the lowest possible frequency e g 200 MHz 2 Set STOP FREQ to the highest possible frequency e g 500 MHz 3 Set REFERENCE LEVEL to the highest signal level you expect e g 0 dBm 4 Wait for the sweep to complete 5 Ifa signal is identified click MKRCF to move the signal to the center of the graticule 6 Under the Span Controls section click the down arrow to decrease span until your span is 50 MHz 7 Select Settings gt Signal Track gt ON 8 Under the Span Controls section click the down arrow until your span is 50 KHz Your signal should remain centered horizontally in the graticule during this process Notice the change in sweep speed from wider bandwidths RBW gt 6 5 KHz VBW AUTO to narrower bandwidths RBW or VBW lt 6 5 KHz This is due to the software internally changing modes of operation For wider bandwidths a firmware controlled sweep collects small pac
29. o Bandwidth This will smooth out the zero span data This must be set to a value larger than your demodulated audio bandwidth 4 If you want to use video triggering Check the appropriate box and fill out the trigger controls a trigger level is the approximate minimum power in dBm that will trigger the sweep b The trigger position sets the amount of pre trigger data to display as a percent of sweep time This allows you to see data both before and after the trigger event 5 Enter your Sweep Time in milliseconds This becomes your X Axis on the graticule display 6 Select amplitude vs time or Frequency vs time to view and measure AM or PM respectively You may use the markers as above to take basic measurements SINGLE sweep will make these measurements much easier to make 3 2 1 Capturing Pulses in Zero Span To capture a pulse click ZERO SPAN as before then click VIDEO trigger You must supply the minimum amplitude to trigger the sweep When you begin a video triggered sweep data is collected continually in the background When a signal with sufficient amplitude is detected the software continues to collect data until the sweep is complete 3 3 Understanding Your Signal Hound The Signal Hound switches between two intermediate frequencies and three IF gain settings when measuring signals and performing image suppression Most of this occurs automatically and can be ignored but may cause unexpected behavio
30. p is complete To activate select Settings gt SYNC TRIGSSYNC OUT There is 220 ohm internal impedance for this output 23 THEORY OF OPERATION 5 Theory of Operation Learn about the internal blocks that make up the Signal Hound maximum bandwidth of 250 KHz It receives up to 2 Megabytes of I Q data each second which it processes into a trace To bring you a low cost compact spectrum analyzer we used recently developed high level RF integrated circuits The block diagram below illustrates the major elements of the design Image rejection is accomplished by mixing high side and low side sometimes with separate IF frequencies then masking together the results he Signal Hound is built around a narrow band IF to bits receiver with a ER IC MIXERS DUAL IFs RF Preamplifier 2 RF IN os gt 01588 RHR Ben a 69 Figure 5 Simplified Block Diagram 5 1 1 The Four Sweep Modes gt Zero Span the Signal Hound operates by continuously mixing a fixed LO frequency with the RF input and displaying the instantaneous amplitude or frequency of that signal as a function of time gt Below 6 5 KHz RBW or VBW the Signal Hound processes the spectrum in 200 KHz sections or smaller by mixing two fixed LO frequencies typically one above the RF frequency
31. port gt CSV Exports trace data to a spreadsheet file in linear power units Print Used to print the Graticule trace data and settings The title is printed as well Free PDF print utilities such as PDF995 are available to print to and save a PDF file 2 3 2 EDIT gt Set Title Enter optional title This will appear across the top of printouts 2 3 3 VIEW gt Toolbar Shows or Hides the toolbar icons gt Status Bar Shows or Hides the status bat which shows the mouse cursor s location inside the graticule gt Split Selects the split between the graticule and control panel useful to resize ot hide the control panel gt Color Scheme Allows you to customize the colors used in the graticule Classic Select yellow trace on black background etc TEP Select green trace on black background etc White Background Select dark green trace on white Custom Select your own colors Save As Default Save your preferred color scheme so that it will always be used 2 3 4 SETTINGS Downconverter Offset Adds a fixed frequency offset to the display and marker readout to compensate for your downconverter LO Assumes low side injection GETTING STARTED 2 3 5 2 3 6 gt gt gt External Reference Look for an external 10 MHz teference If found select and use it Preamplifier Turn the RF preamplifier on or off Turn it on to increase sensitivity and reduce LO feed thru Turn it
32. r in some situations The Signal Hound automatically selects the IF gain based on avoiding compression for the given reference level As the attenuator settings change or the reference level changes the IF gain may change as well This typically occurs between 5 dBm and 16 TAKING MEASUREMENTS 30 dBm depending on settings This may affect the noise floor but should not affect your measurements Some Local Oscillator leakage occurs at frequencies offset by approximately 2 9 or 10 7 MHz from the RF center frequency This is a concern when connecting to an antenna or sensitive device A preamplifier or circulator may be used to reduce the LO leakage to an acceptable level You may also increase the attenuator setting to reduce LO leakage 3 4 Measuring Harmonics A harmonics utility is included for one click measurements of harmonics use this utility you must span down to 100 KHz or less narrower spans will give a lower noise floor center the signal on the graticule then select Utilities gt Harmonics Viewer from the Menu When the sweep completes you will see the relative amplitude of the fundamental first four overtones This utility is for amplitude measurements only The frequencies assumed to be integer multiples of the fundamental When your measurements ate complete select Utilities gt Harmonics Viewer to un check this utility and resume normal operation 3 5 Measuring Phase Noise A phase noise utility
33. reviously saved state select File gt Recall State from the menu A standard File Dialog box will open prompting you to select a file Once you select a file it will be instantly displayed on the Graphical User Interface GUID 4 1 2 Printing Printing is handled through the default Windows print and print preview dialog boxes accessed by selecting File gt Print It is similar to printing from an Office application Print to any installed printer Everything on the GUI above and below the graticule is printed An optional title set by selecting Edit gt Set Title is printed along the top 21 ADDITIONAL FEATURES 4 1 3 Listening to Demodulated Audio Frequency MHz IF Bandwidth Modulation Mode FM De emphasis usec Pee 27 fzokuz Fm Changes When you identify a modulated signal and wish to listen Figure 4 Audio Listen to the modulation you may position your marker on the signal in question and select Utilities gt Audio Listen If you do not place a marker the CENTER FREQ will be used This frequency will be pre loaded into the dialog box on the left Additional demodulation options will be preloaded with the last values used or default settings Please have span set to 200 KHz or less before entering Audio Listen mode to ensure device is set up correctly and on frequency Frequency represents the center frequency of the RF cartier Modulation Mode may be set to AM FM SSB upper or lower sideband or CW
34. t 10 dBm power level Self Test To use the self test connect the SELF TEST to the RF IN This checks the attenuator mixers broadband power detector RF and IF signal paths and 1 0 demodulator TRACE gt gt Copy Trace A to Stores a copy of trace A the main trace displayed into trace B or C and displays the copied trace Show Hide Displays or hides traces or trace math 10 GETTING STARTED e Trace A Trace B Trace C Shows or hides selected traces e Trace B A or A B Displays trace math on a new scale You will be prompted for scale information A B or B A may be shown gt Limit Lines Displays or hides a lower limit line and an upper limit line 2 3 7 Utilities 2 3 8 gt Audio Listen Opens a dialog box with controls for demodulating audio AM FM SSB and CW available For SSB 30 KHz IF is recommended For best sensitivity have your reference level set to 40 dBm and your attenuator set to 0 dB before opening the Audio Listen dialog Broadband Signal Peaking is a mode that combines fast sweeping with high sensitivity for locating and peaking broadband gt 5 MHz bandwidth low level signals The preamplifier is automatically turned on in his mode When selected a dialog box opens Select a frequency step of 1 2 or 5 MHz Check the maximize sensitivity box if you are hunting for a small signal This will set the reference level to 50 dBm and attenuator to 0 dB Pleas
35. t is converted to an amplitude This amplitude is then filtered by the Video Bandwidth filter This is implemented as a simple rectangle averaging window Video bandwidths are available from 0 1 Hz to 250 KHz typically in powers of 2 VBW must be equal to or less than RBW AUTO To reset either RBW or VBW to automatically use the default setting for each span click AUTO GETTING STARTED 2 2 6 2 2 7 Video Detector Settings As the video data is being processed the minimum maximum and average amplitudes are stored Minimum maximum average or Min amp Max may be displayed When converting from I Q data to unprocessed amplitude data the amplitude may be represented as voltage linear power or logarithmic power data Select linear power for RMS power measurements Logarithmic power is closest to a traditional spectrum analyzer in log scale For older or underpowered computers select BYPASS to skip video processing Sweep Time A slider is available to select fast or slow sweep times Fast sweep times process a small amount of data per trace and update quickly Slow sweep times process a large amount of data and update slowly Use slower sweep times for longer RMS power readings or to observe any given spectral window for a longer period of time o For Zero Span there is a separate Sweep Time control that allows you to explicitly set this parameter This control is secondary to the RBW and VBW contro
36. ter results For frequencies above 500 KHz the RF preamplifier may be turned on to further reduce the noise floor Video averaging may be required for a stable amplitude reading 3 1 5 Measurements Near The amplitude displayed is the sum of all energy present in the IF This includes the signal as well as noise and residual responses Measurements of signals less than 10 dB above the noise floor will have a measurable amplitude error due to the addition of noise To compensate for this subtract the amplitude with no signal present the noise in linear power units from the amplitude with signal present to calculate the signal level Please note that the measurement uncertainty will increase from this process 3 1 6 Capturing Pulsed or Intermittent Signals To capture an intermittent signal of unknown frequency MAX HOLD may be used If the duration of the signal is less than the displayed sweep time turn off image rejection to capture the signal For very short signals video bandwidth should be set to maximum Sweep Time may be turned to slow 3 2 Viewing Modulation A signal s modulation envelope may be viewed or measured using ZERO SPAN To use zero span follow these steps 15 TAKING MEASUREMENTS 1 Click the ZERO SPAN button A popup should appear with the Zero Span controls 2 Select your desired Resolution Bandwidth This is equivalent to the intermediate frequency or IF Bandwidth 3 Select your desired Vide
37. ts a digital low pass filter windowed sinc for the demodulated audio to reject high frequency audio noise The filter rejects audio modulation above the selected cutoff frequency Fe Audio Band Pass Natrow band audio filter 160 Hz BW to select a single modulation frequency and reject all others 18 TAKING MEASUREMENTS The Synchronous Average Level Detector is used to select between two relative amplitude measurement modes o There are two gain ranges for RF level If your amplitude readings must span both ranges you must take a stable power level reading in the overlapping region 45 to 65 dBm to properly calculate relative power When the RF level is in this overlapping area the Low Power Range button will become available Select the low power range to generate a correction for spanning the two gains Once this correction value is calculated an asterisk will appear by Relative Power indicating you are in the high sensitivity range You can now step power across the full dynamic range When you need to go above 45 dBm or so select High Power Range again There is no limit to the step size except for the compression point in each range Checking the Synchronous Average Level Detector box will zero the relative power reading and enable the synchronous detector Use this to measure a clean phase locked RF CW signal over a 140 dB dynamic range Use a common external 10 MHz reference Un checking
38. ur package for shipping damage before opening Your box should contain a USB cable a CD ROM and a Signal Hound USB SA44B PREPARING FOR USE 1 2 Software Installation The Signal Hound is operated from a Windows based PC using our application software 1 2 1 System Requirements The Signal Hound software and drivers are compatible with Windows operating systems You must have at least 500 MB of free disk space 1 GB of RAM USB 2 0 and a 1 GHz processor and internet access for a one time calibration data download Your computer must have the Microsoft net framework version 3 5 or newer installed If you have Windows 7 or Windows Vista with automatic updates turned on you should already have this If you do not already have a newer version please install it from the CD The software connects to the internet to download a temperature correction file An internet connection is required the first time you run the software 1 2 2 Install the Signal Hound Software e Run setup msi from the CD by double clicking the file Follow the directions on the screen You must have administrator privileges e If you did not see the Visual C 2008 redistributable install during setup you must tun 100186 86 from the CD and follow the instructions e If you did not see a command prompt pop up during the install manually install the USB drivers by running CDM20802_setup from the CD Signal Hound software is now installed
39. using the Control Panel and Menu The data is returned over USB and displayed in the Graticule as a Trace For specific measurements the Marker and Status Bar may be used as well See Figure 1 for the locations of these items MENU d MARKER GRATICULE CONTROL PANEL TRACE STATUS BAR Figure 1 The Signal Hound Graphical User Interface GUI 2 1 The Graticule The Graticule contains ten vertical and ten horizontal divisions to display trace data The trace data is the processed and formatted data from the Signal Hound displayed in the graticule Above and below the Graticule you will find indicators regarding settings and markers The indicators include GETTING STARTED gt REF Reference level top left The reference level is the signal amplitude for the top Graticule line gt DB div Amplitude scale near top left in dB per division of the Display Window In Linear scale this will be mV div ATTEN Attenuator setting top center The internal electronic attenuator may be set to 0 5 10 or 15 dB INT EXT REF Top tight Indicates whether internal or external reference is selected START CENTER STOP Bottom left center and right of Display Window Start center and stop frequencies representing the frequency of the left center and right Graticule lines respectively Markers may be placed anywhere on the trace by gt RBW Selected Resolution Bandwidth left
40. z RF Probe p n P 20A made by Auburn Technology www auburntec com 32 REVISION HISTORY 9 Revision History Software Version 2 04 Initial Release of 2nd Generation software Firmware Version 2 02 Added support for broadband signal peaking utility 33 WARRANTY AND DISCLAIMER 10Warranty and Disclaimer Copyright 2010 Test Equipment Plus All rights reserved Reproduction adaptation or translation without prior written permission is prohibited except as allowed under the copyright laws 10 1 1 Warranty The information contained in this manual is subject to change without notice Test Equipment Plus makes no warranty of any kind with regard to this material including but not limited to the implied warranties or merchantability and fitness for a particular purpose Test Equipment Plus shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing performance or use of this material This Test Equipment Plus product has a warranty against defects in material and workmanship for a period of one year from date of shipment During the warranty period Test Equipment Plus will at its option either repair or replace products that prove to be defective 10 1 2 Warranty Service For warranty service or repair this product must be returned to Test Equipment Plus The Buyer shall pay shipping charges to Test Equipment Plus and Test Equipment Plus
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