HW-16 Pwr Supply Rebuild? Sort of!

[Gareth Gammon]

Many thanks to all who responded to my question re capacitor
values. I think I replied personally to all who answered,
but if I missed you my apologies and thanks. And to Ed,
K6UUZ,  special thanks, you prompted me to look further and
you were right on.

These parts are burned up starting at the power supply.

The fuse, R205, R206, R46, R47, R48 (rf gain pot)

I checked out the rectifier diodes, D202, 203, 204, 205 all
okay

All four sections of filter Cap C204 test okay with the VOM.
(I might replace one or more of  these anyway: the set had a
little hum when it worked)

Tubes V1 (rf amp) and V4 (if amp) both test good (no shorts,
good output). I checked these tubes as the rf gain pot
controls both of them and suspected they might be damaged.
Fortunately not.

Looking on the driver/final side of that circuit there
doesn't seem to be any burned out parts.

Once I had removed one wire (and the resistors) from the
triangle section of filter cap C204 it tested okay (it
initally tested as a dead short). Following that red wire
led me to the pcb traces with the burned out R46, R47 and
then to the burned rf gain pot.

Now the question. There does not seem to be any other damage
so this could be an easy fix if there is nothing else wrong.
To those with way more diagnostic/repair knowledge than I
have, could the damage have been caused by the rf gain pot
shorting out to ground or should I be looking for something
else that caused the pot to burn up?  I might as well find
out all the problems before replacing parts so I don't have
to replace them again. Diagnostics by smoke signal is
expensive!!

Any help would be appreciated

Thanks again
Gareth VE7CGG

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