TROUBLESHOOTING AND REPAIR
RF LEVEL/AM
7. Alternately measure +PEAK and -PEAK, and adjust the AM depth adjustment,
R10, until the readings are symmetrical about 90%.
8. Reinstall the AM depth adjustment access screw.
Mod Control PCA RF Level Adjustment, R20 6D-15.
TEST EQUIPMENT:
• Power meter
• Power sensor (High-Level)
REMARKS:
The UUT must be operated at room temperature for at least one hour with the module
plate covers in place before continuing with this adjustment procedure.
This adjustment is required if any of the following events occur:
• The Output PCA, the Modulation Control PCA, or the Attenuator/RPP
Assembly has been replaced.
• The AM depth adjustment is made.
• The level DAC or any associated components are replaced.
• The RF level adjustment has been inadvertently changed.
CAUTION
The RF level adjustment directly affects the output level and should not be
made indiscriminately.
PROCEDURE:
With the UUT programmed to +9 dBm, adjust the RF level adjustment, R20, for +9
dBm output as measured with the Power Meter.
1. Program the UUT to SPCL 01, 350 MHz, and +9 dBm.
2. Zero the power meter.
3. Remove the RF level adjustment access screw from the bottom module plate
cover.
4. Connect the power sensor to the UUT RF connector.
5. Adjust RF level adjustment, R20, for a reading of exactly +9 dBm on the Power
Meter.
6. Reinstall the RF level adjustment access screw.
6D-14
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