In 1975, I worked for a marine radio company called Konel.
I worked on their first synthesized radio, which I inherited
from another designer. The original design had a VCO that
was quite microphonic. We didn't even bother with beeswax,
we potted itin Red Glyptol. Even that wasn't good enough
for two reasons. The speaker was in the same box and the
sailors would turn it up so you could hear the radio over
the engine noise. Also, the 10,000 HP engines on tug boats
produced a lot of vibration which got into the VCO.
I designed a VCO with an inductor printed on the PC board,
and that did the trick. A few months later, Konel went
out of business and few if any radios were produced.

Rick N6RK


"Larry Gagnon" wrote in message
news
I posted a few days ago about repairing a VHF marine radio. Thankfully I
solved my problem, locating three cold solder joints in the VCO, which
entailed removing metal shields and all the beeswax that coated all the
components. That was character building work!

I gather the beeswax is to ensure rigid components to maintain stability
of the oscillator? Any other reasons for it? Is it necessary for me to
remelt the old wax and spread it around as before, or can I get away with
just reshielding the VCO?

Any suggestions appreciated.

Larry VE7EA

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