XIEGU
Product Maintenance Manual G90/G90S Portable Short-Wave Transceiver
XIEGU All Rights Reserved Version No.: 1.0 2022-07 Page
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Fault phenomenon: during static current adjustment, the current does not change
Maintenance methods:
1. Disconnect the transmitting small signal line and press the hand
microphone so that the whole device enters the transmitting state.
2. Check the voltage status at each point:
Checkpoint
Voltage V
Name
B12
2.5
～
4.55
Power tube grid voltage (cut-off
- amplification)
B13
2.5
～
4.55
Power tube grid voltage (cut-off
- amplification)
B14
13.8
Power tube VCC voltage
B15
13.8
Power tube VCC voltage
3. If the voltage of check points B12 and B13 is 0 or lower than the
above standard voltage, it indicates that there is a problem with the
power tube grid power supply or there is a short circuit in the power
tube grid.
3.1 Power off the whole device and unplug the power cord. Measure
whether the grid of two RD16HHF1 power tubes is short-circuited to
the ground.
3.2 Start up to enter the transmitting state, and measure whether the
voltage at the following check points is normal:
Checkpoint
Voltage V
Name
B16
6
Transmitting reference
voltage
B17
6
Transmitting reference
voltage
4. If the above steps are normal, check the following points:
Checkpoint
Voltage V
Name
B18
13.8V
Transformer secondary
voltage
B19
13.8V
Transformer secondary
voltage
B20
13.8V
Transformer primary voltage
B21
13.8V
Voltage at the choke
If there is a point with voltage of 0 among the above check points,
check whether there is false welding at the four points.
