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Old March 27th 07, 10:13 PM posted to rec.radio.amateur.equipment
[email protected] amp.tech@yahoo.com is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 2
Default TS-930s transmit problem

I just repaired a TS-930, that had the RF PA driver transistors blow
up due
to overheating of the power supply.


your VC goes full scale ? ? ! ! ! ! ! ! up to 42 votls ! ! !
it should go to 28 Volts.

it sounds like the power supply pass transistors failed, and shorted
out, ( due to heat )
and put the 40 volts to the RF Final PA. This will blow the driver
transistors.
A common problem in this radio.

are the fans working? it is important that the fan to the power
supply comes on,
or the power supply will over heat, or results I just mentioned will
happen.

what is the serial number to your radio ? ?

Kenwood added to the power supply circuit, later in production,
but it will not help the overheating problem.