Figure 69: Verifying Vhf Duplexer Isolation - Connecting Duplexer Cable Assembly; Verifying Vhf Duplexer Isolation - Motorola ASTRO 25 GTR 8000 Manual

Figure 69: Verifying VHF Duplexer Isolation — Connecting Duplexer Cable Assembly
5.10.4.7.1

Verifying VHF Duplexer Isolation

Procedure:
1 Connect test equipment as shown in
Test Equipment on page
2 Observe and note the level in dBm as shown on the service monitor.
3 Connect the test equipment to the duplexer as shown in
Isolation — Connecting Duplexer Cable Assembly on page
4 Observe and note the level in dBm as shown on the service monitor. (If no number is displayed,
consider isolation to be greater than 105 dB, which exceeds the specification.)
5 Subtract the absolute number noted in step 4 from the number noted in step 2. The difference
should be less than 75 dB to meet specification for isolation.
6 Repeat steps 1 through 5 for Low-Pass/High-Notch cavities with the following exceptions:
a Set service monitor for Rx or Tx frequency, whichever is higher.
b Connect service monitor to Low Pass duplexer input (cavity #1).
Figure 68: Verifying VHF Duplexer Isolation — Connecting
174.
Chapter 5: GTR 8000 Base Radio Optimization
Figure 69: Verifying VHF Duplexer
175.
MN003286A01-E
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