Motorola MTR2000 T5544 Instruction / Field Service Manual page 130

Troubleshooting
Verifying Receiver Circuitry
CAUTION
CAUTION
16
Performing this procedure requires that the station be taken out of ser-
vice. It is recommended that, unless the station is already out of service
!
due to an equipment malfunction, this procedure be performed during
off-peak hours so as to minimize the disruption of service to the system
subscribers.
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.
Introduction
While most module faults can be detected by running the station diagnos-
tics provided by the RSS, the following procedure provides a more tradi-
tional method of troubleshooting the receiver circuitry. This procedure is
useful in the event that the RSS is not at hand or for some reason cannot be
utilized (PC malfunction, etc.).
This procedure allows the service technician to make minor adjustments
and verify proper operation of the station receive circuitry, including:
• Receiver Module
• Power Supply Module
• Station Control Module
In general, the receiver circuitry is exercised by injecting and measuring
signals using a Motorola R2001 or R2600 Communications Analyzer (or
equivalent). Incorrect measurement values indicate a faulty module(s);
measurement values within the acceptable range verify proper operation
of the above listed modules and circuitry.
Required Test Equipment
The following test equipment is required to perform the procedure:
• Motorola R2001 or R2600 Communications Analyzer (or equivalent)
• Male N-type to Male N-type coaxial cable
• RJ-45 to BNC 15cm (6 inch) cable; part # 3083191X02
• Service Speaker; part # HSN1000
• Service Speaker adaptor cable; part # 0185180U01
• Dummy Load (50Ω, station wattage or higher) required for repeater
stations only
68P81096E17-E
09/30/05