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Rev. 1.0

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Summary of Contents for COM-120B

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Page 3: ...advanced features offered by the COM 120B in a minimal amount of time The Operators guide and Programmers manual are also included if you would like to gain even more detailed information We invite y...

Page 4: ...eviation DTMF Decode Transmitter Distortion Receiver Testing Sensitivity Audio Output Power Cross band Duplex Spectrum Analyzer Filter Tuning Cable Fault Return Loss If you need assistance or have any...

Page 5: ...ting Receiver Half Duplex testing 13 dBm Tracking Generator Output Transmitter Input Up to 50 Watts Continuos The Antenna port is designed for low level off the air signals but has input protection fo...

Page 6: ...rnal Mod source for radio under test Scope DVM Input 200 VRMS Max AUDIO DATA SINAD IN 15mV 15V EXT MOD IN 2 kHz Vpk Narrow 10 kHz Vpk Wide DEMOD OUT AUDIO DATA GEN OUT 0 1 7 VRMS External Audio Analys...

Page 7: ...ection to PC 10 MHz Ext Reference Input Optional GPIB Interface Battery Compartment Replaceable Battery Carry a Spare Ext DC Input 12 30 VDC Master Power Switch LID Storage Unit AC Line Cord DC Line C...

Page 8: ...s to allow repair calibration and diagnostic evaluations of communications systems The COM 120B organizes test functions into screens that can be selected and altered to perform specific tests A power...

Page 9: ...he COM 120B s rear panel receptical and apply power with the power switch located in the lower left corner of the instrument The COM 120B will begin it s power on sequence followed by a selftest The S...

Page 10: ...a numeric field such as the RF frequency 1 Position the cursor the field label RF 2 Use the numeric keypad to directly enter the frequency and terminate entry by pressing the ENTER key OR 3 Press the...

Page 11: ...ng the arrow keys to position the cursor to the desired selection Press the ENTER key to terminate the selection A Zooming feature allows expanded controls for the Scope Spectrum Analyzer and Meter fu...

Page 12: ...res to be accessed When a meter function is zoomed the meter will display a bar graph scope or spectrum analyzer and meter control functions Press the REC key to return to the Receiver screen Pressing...

Page 13: ...edure below 1 Press the key 2 Press the F3 key STORED FILES to access the file directory 3 With the arrow keys position the cursor to the filename SETUPS APP and press the F1 key OPEN 4 This has activ...

Page 14: ...Rev 1 0 Page 14 REC Transmitter Test Screen Exploded view of the function screens that are available in the REC screen...

Page 15: ...N position and set to Channel 2 3 It is not necessary to connect any audio cables at this time The following procedures will lead through the process of Finding an unknown transmitter frequency Freque...

Page 16: ...ed and the COM 120B is monitoring the Power meter for the presence of RF Power 6 Key the Transmitter and the COM 120B will switch screens to the stand alone spectrum analyzer to find the transmitter s...

Page 17: ...g the cursor to the RF ERROR label and pressing the F1 key ZOOM to expand the meter to full screen mode Remember the TAB key Frequency tuning can be easily done by setting the Range to a fixed range S...

Page 18: ...front panel Positioning the cursor to the RF Frequency field allows configuration of the signal find features The entire RF spectrum or a small piece of the RF spectrum can be searched 1 Set Frequency...

Page 19: ...s microphone 6 The voice deviation can be observed on the High Performance Scope as well as the Deviation meter Additionally the RF Power and Frequency can be evaluated 7 Adjust the COM 120B s volume...

Page 20: ...d scope 10 With the Transmitter keyed press the function keys that are labeled PK HOLD and MIN HOLD The scope display will now keep the maximum and minimum deviation extremes on the scope for evaluati...

Page 21: ...e COM 120B System Setup Utility software 3 The menu to the right will appear 4 Select STEP 3 by positioning the cursor and pressing F1 Execute 5 The COM 120B will configure itself for testing Transmit...

Page 22: ...he COM 120B System Setup Utility software 3 The menu to the right will appear 4 Select STEP 3 by positioning the cursor and pressing F1 Execute 5 The COM 120B will configure itself for testing Transmi...

Page 23: ...B System Setup Utility software 3 The menu to the right will appear 4 Select STEP 4 by positioning the cursor and pressing F1 Execute 5 The COM 120B will configure itself for decoding Transmitter DTMF...

Page 24: ...will be used to simulate pressing keys on a radio s DTMF keypad The COM 120B s DTMF generator will externally modulate the transmitter and the COM 120B s receiver and DTMF decoder will decode the tran...

Page 25: ...B System Setup Utility software 3 The menu to the right will appear 4 Select STEP 5 by positioning the cursor and pressing F1 Execute 5 The COM 120B will configure itself for testing Transmitter Disto...

Page 26: ...z deviation on the Deviation Meter 2 If necessary position the cursor to the AF GEN OUT field Press F1 to ZOOM and adjust the audio injection level to achieve 3 0 kHz deviation 3 The audio distortion...

Page 27: ...your own radios you may do so at this time Use the software for setups as you did with our demonstration radio Begin by using the Signal find feature to find your transmitter frequency and the rest o...

Page 28: ...function screens that are available in the GEN screen The generate screen provides all of the features that are required to provide stimulus to a receiver to evaluate performance characteristics The...

Page 29: ...identifies what sources are turned on GEN1 indicates that FGEN 1 is turned on GEN1B indicates that FGEN1 is turned on but is in BURST mode The Gen 1 Source field can be configured for a standard 1 kHz...

Page 30: ...he cursor and pressing F1 Execute 5 The COM 120B will configure itself for testing Receiver Sensitivity Interconnect 1 Connect the COM 120B s T R port Generator Output to the Antenna Input of the Radi...

Page 31: ...radio s reciever 4 Position the cursor to the Level field TAB 4 ENTER 5 Press the ENTER key to highlight the RF Level value and adjust with the Knob control to reduce the level until the COM 120B s S...

Page 32: ...ements or turn Averaging OFF for Automatic measurements Move Cursor to RF LEVEL TAB 2 ENTER Select SINAD and set the desired SINAD point 12 or 20 dB typical Activate Auto SINAD S On OFF STAND BACK AND...

Page 33: ...Rev 1 0 Page 33 DUPLEX Operation Mode Duplex Mode Simultaneous Generate and Receive operation for Full Duplex Any Offset between Generate and Receive frequencies in 2 5 kHz steps...

Page 34: ...ile the RF Signal generator is being used to stimulate the Receiver at the channel frequency The Duplex screen is also commonly used to test cross band repeaters The generator could be used in the VHF...

Page 35: ...s the Receiver test procedure There are other tests that can be performed on the receiver but are beyond the scope of this guide at this time Please turn the radio power to the OFF position now and re...

Page 36: ...AUX RF Output to the Antenna Input of the COM 120B This will configure the COM 120B to zero out test cables for making insertion loss measurements Setup 1 This COM 120B has been pre configured for co...

Page 37: ...he ENTER key to highlight the value Use the left and right arrow keys to select either the 1 or 1 db digits and then use the Data Scroll Knob to adjust the Tracking Generator level for a 0 dBm referen...

Page 38: ...igned the image to the right will be displayed The left side shows the pass band while the right side shows the reject band With the current setup examine the left side for insertion loss This can be...

Page 39: ...ite tuning of frequency Toggling the input attenuation between 0 and 30 dB while tuning allows monitoring of both the reject notch depth and the pass band insertion loss Swap the Cable and load betwee...

Page 40: ...ware 3 The menu to the right will appear 4 Select STEP 9 by positioning the cursor and pressing F1 Execute Note This item offers a help screen accessible by pressing the F3 key 5 The COM 120B will con...

Page 41: ...minimum point of the first dip 5 Record the marker frequency as F1 6 Position the marker to the second dip and record the frequency as F2 7 Calculate the difference F2 F1 The velocity factor for RG 58...

Page 42: ...e 2 Connect the Bridge Source Port to the COM 120B s AUX RF Output 3 Connect the Bridge Reflected Port to the COM 120B s Antenna port Setup 1 This COM 120B has been pre configured for common Analyzer...

Page 43: ...testing Return Loss 6 Connect the Load port of the Return Loss bridge to the 160 MHz port of the Duplexer Filter 7 Connect 50 ohm terminations to the remaining ports on the duplexer 8 The resulting r...

Page 44: ...If you would like information or assistance with tests not covered by this procedure please contact our technical staff for assistance at 1 800 835 2352 and select menu item 1 You will be able to spe...

Page 45: ...Digital Voltmeter Audio Level Meter Dual Audio Function Generators Data Generator DCS DCS INV DTMF Generator Encode Decode DCS DTMF CTCSS RF Frequency Error Meter and Counter FM Deviation Meter AM Mod...

Page 46: ...009 Tone Remote IMTS MTS 10 PS 20 PS Data Generator BER Meter AC3007 MPT 1327 Trunking AC9161 Clear Channel LTR Trunking AC3014 EDACS Trunking AC3016 7 5 kHz IF Filter AC9162 SSB Filter 120B 8xx Micro...

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