Codan NGT 2010 RF Technical & Service Manual page 556

High power—Fault finding and adjustments
Adjusting the power supply operating area
Drawing
NOTE
To adjust the power supply operating area:
1
1
1
1
1
1
1
1
1
1
Adjusting the input attenuator
Drawing
If it is found during testing that the amplifier output is controlled by the NGT rather than
the power amplifier, this indicates that the gain of the power amplifier is low. This can be
increased by removing the link X1 from the Splitter 2-way (500 W) PCB or Splitter
4-way (1 kW) PCB.
242
08-05978 (sheet 1),
The transceiver does not have to be in Service mode to perform this
adjustment.
Ensure there is no audio drive to the NGT.
Use a cliplead to connect +5 V (X4) to the 10-pin header pin 4 (P1/4).
NOTE The header can be removed for this adjustment.
Hold down PTT.
Set the Voltage Adjust preset potentiometer R7 to give 50.0 V DC at X2.
Remove the cliplead, and check that the voltage at X2 drops to approximately
33 V DC.
Using an active load connected from X2 to ground, set the load current drain to
9.5 A.
Adjust the Current Limit preset potentiometer R12 to give 43.6 V DC at X2.
Move the active load to output terminal X3, and set the Current Limit preset
potentiometer R112 to give 43.6 V DC at X3.
Release PTT.
Repeat the above tests for the other Power Supply PCB (3062 only).
08-05997 or 08-05999
08-05978 (sheet 2) and
NGT Transceiver System Technical Service Manual
08-05978 (sheet 3)