User's Manual

68P81093C75-A 9-15
IMPORTANT! If the station operates as a repeater, the transmit output from
the station must be connected to a dummy load to prevent
over-the-air broadcast during receiver testing.
Verifying Receiver
Circuitry Procedure
Step 1. Connect test equipment by performing Step 1 through
3 shown in Figure 5.
NOTE: The cover plate over the SCM side of the chassis
must be removed to perform these tests.
Step 2. Disable PL and carrier squelch by repeatedly pressing
the PL/CSQ/Off button until receiver noise is heard
through the handset (or external speaker). Refer to
Figure 3 for the location of the PL/CSQ/Off button. If
no audio is heard, suspect the following:
• Faulty Receiver Module
• Faulty Station Control Module
• R2001 is outputting a carrier signal
Step 3. Set R2001 to generate a 0.5 µV (-13 dBm) FM signal
at the PDR 3500 receiver frequency, modulated by a
1 kHz tone at 3 kHz deviation. The 1 kHz tone should
be audible through the handset (or external speaker).
If no audio is heard, suspect the following:
• Faulty Station Control Module (2.1 MHz
reference)
• Faulty Receiver Module
• Faulty antenna-to-Receiver preselector RF cable
• Faulty R2001-to-station RF cable
• Duplexer/station receive frequency mismatch, or
faulty duplexer