Motorola APX 3000 Basic Service Manual

Basic Troubleshooting: Transmitter Troubleshooting 9-3
9.4 Transmitter Troubleshooting
Table 9-4 lists the possible causes of, and corrections for, transmitter problems.
Audio Distorted or Not Loud
Enough
Synthesizer Not On
Frequency
Check synthesizer frequency by measuring the
transmitter frequency; realign if off by more than
±1000 Hz
RF Sensitivity Poor 1. Synthesizer Not On
Frequency
Check synthesizer frequency by measuring the
transmitter frequency; realign if off by more than
±1000 Hz
2. Antenna Switch/
Connector
Send radio to depot
3. Receiver Front-
End Tuning
Check RF front-end tuning for optimum sensitivity
using the tuner
Radio Will Not Turn Off Main Board Send radio to depot
Table 9-4. Transmitter Troubleshooting Chart
Symptom Possible Cause
Correction or Test (Measurements
Taken at Room Temperature)
No RF Power Out 1. TX Power Level or Frequency Check TX power level and frequency
programming (from tuner)
2. No Injection To Power
Amplifier
Send radio to depot
3. Antenna Switch/Connector
No Modulation;
Distorted Modulation
1. Programming Check deviation and compensation
settings using the tuner
2. Main Board Send radio to depot
Bad Microphone Sensitivity 1. Check Deviation and
Compensation
Reallign if necessary
2. Accessories Send radio to depot
No/Low signaling
(PL, DPL, MDC)
1. Programming Check programming
2. Main Board Send radio to depot
Cannot Set Deviation
Balance
Main Board Send radio to depot
Table 9-3. Receiver Troubleshooting Chart (Continued)
Symptom Possible Cause
Correction or Test
(Measurements at Room Temperature)

Motorola APX 3000 Specifications

General

Brand	Motorola
Model	APX 3000
Category	Two-Way Radio
Language	English