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Appendix H: Viavi CX300 Tests 

MAINTENANCE GUIDE   |  MT-4E ANALOG & P25 DIGITAL RADIO SYSTEMS

In the Deviation Levels area of the Service section on the RSS, click on the “Key Tx” button and adjust the Tx 

Balanced Audio Input level adjustment as shown in Figure H-22 until a deviation of +/- 1.5 KHz (narrowband) 

or +/-3.0 KHz (wideband) is measured on the CX300. The high and low limits are set at +/-1.4 KHz to +/- 1.6 KHz 

deviation�

Figure H-22: RSS Transmitter Audio Level Adjustment

Enter the Transmitter Deviation Level reading on the MT-4E Test Sheet.

Configure AF Generator A1 to inject a 300 Hz tone at +10.0 dBm (2.500 Vrms) into the Tx Balanced audio input 

and adjust the audio frequency from 300 Hz to 3400 Hz in increments of 100 Hz and check that the transmitter 

deviation does not rise above +/- 2.5 KHz (narrowband) or +/-5.0 KHz (wideband). The MT-4E Transmitter will 

transmit a maximum deviation at an audio frequency of approximately 1300 Hz.

Enter the Transmitter Maximum Deviation Level reading on the MT-4E Test Sheet.

To adjust the auxiliary balanced audio input, plug the AC-3E Control Card or CI-BC-4E Base Control Card 

into the subrack using an extender card, disconnect the Tx Balanced audio input and connect the Auxiliary 

Balanced audio input to the AF OUTPUT on the CX300. Auxiliary 1 audio input is available on pins C19 and C20, 

and Auxiliary 2 audio input is available on pins B14 and A14. Ensure that NO external devices (eg. tone remote 

adapter or IP router) are connected to the auxiliary audio input. Configure AF Generator A1 to inject a 1.0 KHz 

tone at 0.0 dBm (0.775 Vrms) into the Auxiliary Balanced audio input. Adjust the Auxiliary Balanced Audio Input 

level adjustment (R120 for Aux In 1, R123 for Aux In 2) for deviation of +/- 1.5 KHz (narrowband) or +/-3.0 KHz 

(wideband)�

Enter the Auxiliary Deviation Level (if used) reading on the MT-4E Test Sheet.

Summary of Contents for Viavi CX300

Page 1: ...i Appendix H Viavi CX300 Tests MAINTENANCE GUIDE MT 4E ANALOG P25 DIGITAL RADIO SYSTEMS Appendix H Viavi CX300 Tests MAINTENANCE GUIDE www zetron com...

Page 2: ...n MT 4E Radio System Test Sheet 03 Turning OFF the MT 4E Receiver and Transmitter Modules 04 Audio Connections 05 SYSTEM REGULATOR TESTING 06 System Voltage Testing 06 RECEIVER TESTING 07 Receiver Ana...

Page 3: ...esult of misinterpretation or misuse of this procedure Zetron manufactured products are warranted against defective materials and workmanship This warranty does not extend to damage due to misuse negl...

Page 4: ...he USB ash drive into one of the USB ports and select the Home button then Files Copy the Zetron folder from the USB ash drive to the Disk CX300 Internal folder To recall setups while in the CX300 Com...

Page 5: ...Card remove the control card from the rack for the individual receiver and transmitter tests unless otherwise noted Adapters Cables and Extender Cards Various adapters cables and extender cards are re...

Page 6: ...hen the MT 4E receiver and transmitter channel and bank select lines are connected together in parallel turning the MT 4E receiver or transmitter front panel switch to the OFF position will cause the...

Page 7: ...h clip on type clips Recommended Test Points are Audio Control Card and Base Control Card Extender Card pins EC 96D1 and EC 96K 1 22 Auxiliary 1 Audio Output B11 and A11 Auxiliary 2 Audio Output C1 an...

Page 8: ...c d c a c d c a c d c a c d c a c d c a c d c a F F mA S nS n A A mA mA mV mV V V mV mV V V OFF OFF C C A A A A AA M O C M O C VV TEMPERATURE TEMPERATURE A mA m AA AutoHOLD LOGGING SAVE FAST MN MX SE...

Page 9: ...tion level for the tone in M2 On the Zetron Radio system ensure the receiver is turned on and turn the System Regulator Speaker switch to ON and INT Set the FUNCTION rotary switch to position 3 for Rx...

Page 10: ...Figure H 4 Receiver Distortion Measurement Audio Distortion To check receiver distortion inject 70 dBm RF carrier level into the receiver and measure the distortion on the meter as shown in Figure H 4...

Page 11: ...r reference sensitivity measurements are not within Zetron published speci cations the RF Preselector may need re alignment Refer to the Receiver RF Preselector Alignment and Tuning section Squelch Ad...

Page 12: ...ohms is measured on the AF Level meter of the CX300 as shown in Figure H 4 Figure H 6 RSS Receiver Audio Level Adjustment To adjust the auxiliary balanced audio output plug the AC 3E Control Card or...

Page 13: ...the 1011 test pattern Inject the correct NAC as shown in Figure H 8 and ensure that the receiver is operating There are no speci c measurements to make on this test just verify that the receiver is o...

Page 14: ...8 Click on the Start Test button to start the BER test You should get 0 BER at the 70 dBm default RF carrier level Monitor the BER reading while slowly reducing the RF carrier level as shown in Figure...

Page 15: ...n in Figure H 10 Figure H 10 Receiver RF Preselector Tuning The RF Preselector output is a small RF cable internal in the receiver that terminates in an SMB connector The SMB plugs into J3 on the Rece...

Page 16: ...e correct RF frequency as the Center Freq and ensure the receiver is turned on The lter waveform should appear as shown in Figure H 12 Figure H 12 Receiver RF Preselector To tune the RF Preselector lt...

Page 17: ...s mounted on the Synthesizer beneath the RF Preselector The SMB BNC adapter is required to connect this point to the RF INPUT on the CX300 as shown in Figures H 14 VHF and UHF 400 MHz Receiver and H 1...

Page 18: ...MS Figure H 15 UHF 700 800 900 MHz Receiver Reference Oscillator Connection On the CX300 load Zetron preset 04 Rx Reference from your internal drive as shown in Figure H 16 Figure H 16 Receiver Refere...

Page 19: ...r RF OUT Enter this RF frequency into the frequency on the CX300 The receiver generates this frequency out of the Synthesizer into the CX300 Monitor the RF Error on the CX300 To change the reference f...

Page 20: ...g and ip the other switch to KEY TX or set the switch to NORM and key the transmitter through the RSS The AF Generator A1 is con gured to inject a 1 0 KHz tone at 8 0 dBm 0 308 Vrms into the transmitt...

Page 21: ...SYSTEMS Audio Distortion The distortion meter will read demodulated audio and give you a transmitter distortion reading as shown in Figure H 19 The high limit is set to 3 0 Figure H 19 Tx Distortion a...

Page 22: ...r output will vary slightly with the 10 17 Vdc input Figure H 20 RSS Transmitter Power Level Adjustment Enter the RF Power Output reading on the MT 4E Test Sheet Connect the transmitter to the power a...

Page 23: ...rd or CI BC 4E Base Control Card Change the Audio Filter near the top left corner from 0 3 3 4 KHz BP to 15KHz LP as shown in Figure H 21 for a more accurate deviation reading without CTCSS encode If...

Page 24: ...d The MT 4E Transmitter will transmit a maximum deviation at an audio frequency of approximately 1300 Hz Enter the Transmitter Maximum Deviation Level reading on the MT 4E Test Sheet To adjust the aux...

Page 25: ...Key Tx button and the transmitter will generate the reference frequency out of the RF output into the CX300 Monitor the RF Error on the CX300 To change the reference frequency adjust the softpot slid...

Page 26: ...from the CX300 Figure H 24 Transmitter CTCSS Testing On the CX300 load Zetron preset 06 Tx CTCSS from your internal drive Enter the correct RF frequency on the CX300 set the MIC MODE switch on the fro...

Page 27: ...gured to inject a 100 Hz tone at 18 0 dBm 0 098 Vrms into the Tx Subtone input as shown in Figure H 25 If the internal programming is used to generate the CTCSS tone the AF generator is not used and...

Page 28: ...on and adjust the Narrow and or Wide Internal and or External Subtone Deviation level adjustment as shown in Figure H 26 until a deviation of 0 35 KHz narrowband or 0 5 KHz wideband is measured on the...

Page 29: ...IC MODE switch on the front panel of the transmitter to Digital and ip the other switch to KEY TX or set the switch to NORM and key the transmitter through the RSS Computer running RSS Tx Balanced Aud...

Page 30: ...nto the transmitter balanced input however the CX300 does not demodulate the P25 signal Ensure the correct NAC is being transmitted properly as shown in Figure H 28 The NAC is programmed into the tran...

Page 31: ...n as shown in Figure H 29 and the transmitter will begin generating the test pattern out the RF output Figure H 29 RSS Transmitter Modulation Fidelity Test Pattern Measure the Modulation Fidelity of t...

Page 32: ...ansmitter front panel switch to NORM The MIC MODE switch on the transmitter front panel can be set to either Digital or Analog this test does not make use of the front panel switch TRANSMITTER BUS CNT...

Page 33: ...sing the RJ45 cables Figure H 32 System Analog Duplex Measurement Distortion The distortion meter will read demodulated audio and give you a complete repeater system distortion reading The high limit...

Page 34: ...djusted In the receiver or transmitter RSS enter the Service section and click on LVDS Level A default value of 100 on the softpot slider should be close to matching receiver and transmitter deviation...

Page 35: ...tch on the transmitter front panel can be set to either Digital or Analog this test does not make use of the front panel switch TRANSMITTER BUS CNTL MIC RF OUT A D DIGITAL OFF NORM KEY ANALOG TX MICMO...

Page 36: ...l In some systems the receiver and transmitter may be connected directly together using the RJ45 cables Figure H 35 System Digital Duplex Check There are no speci c measurements to make on this test j...

Page 37: ...35 Appendix H Viavi CX300 Tests MAINTENANCE GUIDE MT 4E ANALOG P25 DIGITAL RADIO SYSTEMS This Page Intentionally Left Blank...

Page 38: ...ist for option pricing Specifications subject to change without notice ZETRON EMEA 27 29 Campbell Court Bramley Hampshire RG26 5EG United Kingdom P 44 1256 880663 F 44 1256 880491 E uk zetron com ZETR...

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