Checking Vhf Duplexer After Tuning; Tuning A Uhf Duplexer; Uhf Duplexer Tuning Set Up; Figure 70: Uhf Duplexer Tuning Setup - Motorola ASTRO 25 GTR 8000 Manual

MN003286A01-E
Chapter 5: GTR 8000 Base Radio Optimization
c Connect terminator to cavity #6.
5.10.4.8

Checking VHF Duplexer After Tuning

Procedure:
1 Ensure all locking screws are tight.
2 Ensure dust covers on all trimmer capacitors are installed.
3 Ensure all tuning rod locking screws (6) are tight.
5.10.5

Tuning a UHF Duplexer

The following procedures are most easily performed with the duplexer module removed from the rack
or cabinet. Be sure to note the transmit and receive frequencies for the particular base radio before
beginning.
If the duplexer module is tuned according to instructions and does not meet specifications for return
loss, insertion loss, and/or isolation, the duplexer must be returned to the Motorola Solutions Support
Center (SSC) for repair.
5.10.5.1

UHF Duplexer Tuning Set Up

Figure 70: UHF Duplexer Tuning Setup

5.10.5.1.1

Setting Up for UHF Duplexer Tuning

Procedure:
1 Disconnect N-type connectors (12) and remove cables (6) from cavities. See
Duplexer Tuning Setup on page
2 For each cavity (6), using an open-end wrench, loosen locknuts (2 per cavity).
176
176.
Figure 70: UHF