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Appendix H: Viavi CX300 Tests
MAINTENANCE GUIDE | MT-4E ANALOG & P25 DIGITAL RADIO SYSTEMS
Modulation Fidelity Testing
In the transmitter RSS, enter the Service section and click on “Test Patterns”. Ensure the transmitter frequency
is in the frequency box. In the Select Pattern window select “C4FM Modulation Fidelity”. Click on the “Key Tx”
button 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 the transmitter as shown in Figure H-30. The transmitter should not read more
than 5% Modulation Fidelity. If the Modulation Fidelity is more than 5%, the transmitter will need to be returned
to the factory for service.
Figure H-30 Transmitter Modulation Fidelity Measurement
Enter the C4FM Modulation Fidelity reading on the MT-4E Test Sheet.
