Codan 2110 series, Repair Manual

Page: 102 / 164

Repair procedures, tests, and adjustments
70 Manpack Transceiver 2110 series Repair Guide
1
Record your results and actions (see page 109, Test sheet for the 2110 series
Manpack Transceiver ).
1
Return to the Repair flowchart (see Figure 29 on page 95 ).
Performing the ALC test
To test the ALC of the transceiver:
1
Set up the equipment (see page 56, Setting up the test equipment ).
1
Select a channel to test.
1
Set the fine output level adjustment on the 0208 to minimum.
1
Switch on PTT on the 0208.
1
Monitor the output power of the RF envelope on the oscilloscope.
1
Slowly increase the audio output level on the 0208 until the RF output power of the
transceiver stops increasing.
This is the ALC threshold.
1
Record the PEP and the output level (see page 109, Test sheet for the 2110 series
Manpack Transceiver ), then increase the audio output level on the 0208 by 10 dB.
1
Record your results and actions (see page 109, Test sheet for the 2110 series
Manpack Transceiver ).
To protect the ALC:
1
Reduce the output level on the 0208 until the RF output power of the transceiver is
3 dB below the ALC threshold.
1
Switch off PTT on the 0208.
1
Record the DC supply current from the power supply.
1
Disconnect the coaxial cable from the 50

connector ( ).
1
Switch on PTT on the 0208.
1
Record your results and actions (see page 109, Test sheet for the 2110 series
Manpack Transceiver ).
1
Switch off PTT on the 0208.
Pass A display on the power meter that shows an increase in RF output
power that is < 0.5 dB (approximately 10 W).
NOTE
Equivalent readings for power meters without PEP and dB scales are
listed in
Table 16 on page 71 .
Pass A reading on the power supply that shows a reduction in the DC
supply current of approximately 50% from the reading taken with
the load connected.