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: there is sudden change of current when the power amplifier is adjusted to
static state
Maintenance methods:
1. First confirm that the static current does have nonlinear changes
(sudden changes) during regulation.
2. Adjust all three adjustable potentiometers to zero.
3. First turn up potentiometers B10 and B11 by 650mA respectively,
and observe whether the change of current is linear during adjustment.
4. Then adjust potentiometer B9 to increase the current by 350mA, and
observe the change of current at any time during the adjustment. Once
there is a sudden increase in current, return the potentiometer B9 to
zero and adjust it again to observe whether the current changes
suddenly. If it still changes suddenly, it can be determined that the
power tube RD06 is damaged.
According to previous maintenance experience, most sudden
changes of current are caused by the damage of RD06.
