9-22
September 27, 2000
68P81093C75-O
The transmitter circuitry is exercised by injecting and measuring
signals using a Motorola R2670 Communications Analyzer (or
equivalent), and analyzing the Bit Error Rate using the RSS.
Measured values outside the acceptable range indicate a faulty
module; values within range verify proper operation of the above
modules and circuitry.
Required Test Equipment
The following test equipment is required to perform the procedure:
•
Motorola R2670 Communications Analyzer with
ASTRO CAI Option (or equivalent)
•
PC running Radio Service Software (RSS)
program
•
Female N-type to Female N-type coaxial cable
•
Dummy Load (50
Ω
, station wattage, or higher).
Required for repeater stations only.
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.
Step 1. Proceed to ASTRO Bit Error Rate Report (located in
Chapter 4 of the RSS User’s Guide, part number
68P81085E35). Follow the instructions for setting up
the test equipment and initiating a BER report using
the RSS.
Step 2. If the BER reading is above 5%, suspect the
following:
•
Faulty Station Control Module (2.1 MHz
reference)
•
Faulty Receiver Module
•
Faulty antenna-to-receiver preselector RF cable
•
Faulty top panel-to-preselector RF cable
•
Faulty R2670-to-station RF cable
Step 3. If you are injecting RF directly into the top panel
receiver port, change the R2670 injection signal level
to:
•
VHF: 0.25 µV (-119 dBm)
•
UHF: 0.35 µV (-116 dBm)
If you are injecting RF through a duplexer, change the
R2670 injection signal level to:
