Motorola PDR 3500 Basic Service Manual page 42

68P81093C75-O
Step 3. Press the PTT button and observe the LED indicators
on the Exciter Module front panel.
• If PA Low or PA Fail LED is lit, suspect the
following:
- Power Amplifier Module failure
- Exciter Module failure
- Loose or bad Exciter-to-PA RF cable
- DIP switches on backplane are set for incorrect
station frequency band. DIP switches should
be set as described in the backplane portion of
the Module Replacement section.
- Faulty forward voltage, control voltage, or
temperature voltage translation circuitry on
backplane.
• If TX Lock LED is off, suspect the following:
- Faulty Station Control Module
- Faulty Exciter Module
- Faulty backplane
Step 4. Measure output power by pressing the PTT button and
observing the reading on the in-line wattmeter.
• If the PA output is not at the proper power (as set
for the particular station), adjust the output power
as described in the Setup and Connections
section of this manual.
• If the station will not output the rated power, and
the output is being measured through a duplexer or
antenna relay, the duplexer could be set for the
incorrect frequency, or it could be malfunctioning,
or the antenna relay could be faulty. Connect the
wattmeter directly to the transmit port (UHF
connector) on the station top panel, bypassing the
duplexer or antenna relay. If the station generates
rated power directly from the PA, suspect the
following:
- Faulty duplexer or transmit frequency
mismatch
- Loose or faulty PA-to-duplexer/antenna relay
cable
- Improperly connected or faulty antenna relay
September 27, 2000 9-13