In , wrote:

wrote:
"Shadow 998" wrote in message
.com...
Hello. I have two Johnson 223 tube type CBs, and they both have the
same problem. They'll run fine for a while, then the radio pops and
the
receive
drops out. It may be out for minutes, hours or days, and then pop, it
comes
back in. It is the same on all channels. I have been frustrated
trying
to
figure this one out for several years now. BTW; it is not an audio
problem
and transmit is unaffected. I have swapped out all the tubes to no
avail.

Find someone to check all the tubes will fix it.

What part of "I have swapped out all the tubes to no
avail", did you not understand?

It might be a relay. Sparky is the guy to ask.

Thanks for the heads-up.

The problem could be any one of several different issues. The first thing to
check is the mic and/or relay contacts which may just be dirty. But I doubt
that's the problem. Another possibility is the audio transformer: like most
radios built at that time, the audio transformer doubled as both the speaker
output and modulation transformer. But the 223 was unique in that it had
seperate windings for each purpose. So the speaker output winding could go out
and you still have modulation, or vice-versa. But again, I doubt that's the
problem.....

The big issue with the 223 was their frequency synth board. The PC board itself
was cheap phenolic crap, the type of early stuff where the traces and pads fall
off if you hold down the soldering iron two seconds too long. Johnson probably
didn't realize that the heat from the tubes would degrade the boards over time.
Anyway, most problems with the 223 are in that board, and I'm betting that's
where the problem is with those radios. There are no replacement boards that I
know of, and repair is tricky (because they are so sensitive to heat). Even if
you can fix it, the chances of it going bad again very soon are very high.

If someone is ambitious, one could strip a good board, scan it, then make and
market some new blanks using a good glass/epoxy material.






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