On Fri, 7 Jan 2005 21:50:07 -0800, "Rick Karlquist N6RK"
wrote:

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

Even British WW2 equipment used beeswax, although the result wasn't
always so good, or perhaps not only English equipment since it was
mentioned in CQ, see http://home.online.no/~la8ak/93a.htm

---
J. M. Noeding, LA8AK, N-4623 Kristiansand
http://home.online.no/~la8ak/c.htm