"Nordic Breeds" wrote in message
...
"Richard Knoppow" wrote in
message
m...

"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.


Both the Mark 1 and Mark 2 models have the 22K resistor in
the Bama schematics. I would check
both C24 and C26 but a leaky C24 is the most likely cause
of overheating in the 22K resistor. A
quick check on the plate and screen voltages of V5 should
point you in the right direction. A tube
socket extender is handy here, but carefully pulling the
tube out and carefully wrapping a fine wire
around the appropriate pins and plugging it back in will
work. C28, C29, and C30 should also be
checked. Silver migration in C28 and C29 could
conceivably case the noise too.

73, Barry WA4VZQ

Looks like a different value to me but both schematics
are sort of low res.




--
Richard Knoppow
Los Angeles
WB6KBL