Service Manual

SRM9000 SERIES SERVICE MANUAL

4.2.3.4 Mute Adjustment

Note. This adjustment has default setting of 1000/2600 and should not need changing except for specific

requirements.

1. Select the Mute/TCXO page and select Open Mute.

2. Set the RF signal generator to the receiver alignment frequency, and adjust the RF level such that

the desired mute opening SINAD (typically 10dB SINAD) is achieved.

3. Select Close Mute and remove the RF input from the radio.

4. Set the Squelch Open and Squelch Close sliders to the fully left position. This ensures the receiver

will be muted.

5. Set the Squelch Close slider to the fully right position.

6. Reconnect the RF input to the radio.

7. Adjust the Squelch Open slider to the right until the mute opens.

8. Reduce the Signal Generator output level by approximately 2dB (or by an amount equal to the

desired mute hysteresis level).

9. Adjust the Squelch Close slider to the left until the mute closes.

10. The mute should now open and close at the desired RF levels.

15.

Note. On revision 9 radios and higher, an additional Tx Audio Balance DAC is also provided.

For these radios, the Tx Audio Balance DAC is defaulted to zero for normal setting. However, for a

more accurate setting, the DC voltage at TP745 needs to be noted during Rx and adjusted by the Tx

Audio Balance DAC to give the same reading (to within 10mV).