TR-800 Service Manual
64
3. Connect a communications test set, such as HP8921 series, or an RF signal generator to the
antenna connector of the duplexer. The test set should be operating in “Generate” mode. To
facilitate “hearing” during the tuning procedures, modulate the RF source with a 1kHz tone at 60%
system deviation.
Tuning the Master Radio
To tune the master radio of the duplexer, begin with the tuning screw closest to the antenna connector of
the duplexer.
1. Set the frequency of the communication test set or generator to the Rx one.
2. Place the master radio in Rx frequency mode defined in Step 1 under “Programming the Radios”.
3. Adjust the level of the communication test set or generator until the master radio emits a weak
signal.
4. Increase the level of the communication test set or generator by approximately 20dB.
5. Adjust the tuning screw of the duplexer for the greatest rejection of the signal. This will appear as a
noisier signal.
Procedures:
5a. Slightly loosen the locking nuts of the tuning screws to allow the tuning screws to turn freely (but
not “sloppy”)
and
5b. Increase the level of the communication test set or generator to maintain an audible 1kHz tone.
6. Repeat Step 4, Step 5, Step 5a and Step 5b for each of the tuning screws on the duplexer. Begin
with the tuning screw closest to the antenna connector and finally tune the screw closest to the
master radio port.
7. Tighten the locking nuts of the tuning screws.
To avoid damage to the tuning screws and to allow fine tuning of the duplexer, do not over-tighten
the locking nuts.
8. Repeat Step 5, Step 5a and Step 5b to fine-tune the master radio of the duplexer.
Tuning the Slave Radio
To tune the slave radio of the duplexer, begin with the tuning screw closest to the antenna connector of
the duplexer.
9. Adjust the frequency of the communication test set or generator to the Tx one.
10. Place the slave radio on the Rx frequency mode defined in Step 2 under “Programming the Radios”.
11. Adjust the level of the communication test set or generator until the slave radio emits a weak signal.
12. Increase the level of the communication test set or generator by approximately 20dB.
Summary of Contents for TR-800
Page 17: ...TR 800 Service Manual 15 Figure 6 5 Figure 6 6 ...
Page 41: ...TR 800 Service Manual 39 Figure Ⅰ Block Diagram ...
Page 81: ...TR 800 Service Manual 79 Packing ...
Page 82: ...TR 800 Service Manual 80 TR 800 Wiring Diagram ...
Page 83: ......
Page 84: ......
Page 85: ......
Page 86: ......