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Old November 13th 09, 11:01 PM posted to rec.radio.amateur.boatanchors
Richard Knoppow Richard Knoppow is offline
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First recorded activity by RadioBanter: Oct 2006
Posts: 527
Default Halli SX 100 Problem found, Need help with cause


"tchrme" wrote in message
...
Partial success on this stubborn problem and it would have
to be my
favorite rcvr too. I traced the thunderstorm crashing
sounds down to
the 2nd converter subchassis. After I pulled it again, I
replaced all
the caps and the resistors since it is such a pain to
access. I
powered it up on test leads to the main chassis and still
heard the
frying thunderstorms. A 22k resistor that I replaced was
starting to
overheat and turned brown. I checked the one I took out
and it too was
burned looking. So.... I need help on what would cause the
overheated
resistor (R24). I can email a schematic to anyone who can
help me out
on this. I double checked all wiring and parts were
replaced one at a
time. Help. Thanks ahead of time. 73 Mike KF6KXG


Have you made tube socket voltage and resistance
measurements? This is a first step and will often point at
problems. I've downloaded the schematics for both versions
of the RX, you appear to have the earlier one (the 22K
resistor is a different value in the later version). I can't
see an immediate suspect but any capacitor in a position to
draw current through the resistor is a suspect. While paper
caps fail mostly by developing a low series resistance I
have encountered shorted ones.


--
Richard Knoppow
Los Angeles
WB6KBL