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

--
********************************
to reply via email remove "fake"
Microsoft will soon release their newest product: a vacuum cleaner.
It will be their only product which doesn't suck.

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

Beeswax is exceptionally good for protection from an
ionic environment (salt water, human body).


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


"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

--
********************************
to reply via email remove "fake"
Microsoft will soon release their newest product: a vacuum cleaner.
It will be their only product which doesn't suck.

Andrew Mitz wrote:
Beeswax is exceptionally good for protection from an
ionic environment (salt water, human body).


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


"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

--
********************************
to reply via email remove "fake"
Microsoft will soon release their newest product: a vacuum cleaner.
It will be their only product which doesn't suck.


Had a Yaesu FT-470R 2m ssb/fm transceiver in recently for repair - VCO
was faulty. The module had been encapsulated in expoxy resin, and took
AGES to chip out with a fine wood chisel (and lots of swearing). Broke
a few components doing it, but could replace them so did. Pig of a job.

I consider this to be the definitive reason why beeswax is a better
potting material for VCO's.

What more do you want? - its cheap, readily available, easy to use,
recyclable, easy to get out for equipment maintenance, smells ok when
melted (better than modern chemicals) - need I say more?

Andrew VK3BFA

I consider this to be the definitive reason why beeswax is a better
potting material for VCO's.

What more do you want? - its cheap, readily available, easy to use,
recyclable, easy to get out for equipment maintenance, smells ok when
melted (better than modern chemicals) - need I say more?

Andrew VK3BFA
Andrew, do you know what the thermal conductivity of beeswax is?
Alan

Alan Peake schrieb:

I consider this to be the definitive reason why beeswax is a better
potting material for VCO's.

What more do you want? - its cheap, readily available, easy to use,
recyclable, easy to get out for equipment maintenance, smells ok when
melted (better than modern chemicals) - need I say more?

Andrew VK3BFA

Andrew, do you know what the thermal conductivity of beeswax is?
Alan

http://www.fao.org/docrep/w0076e/w0076e12.htm
Bruno

Alan Peake wrote:
I consider this to be the definitive reason why beeswax is a better
potting material for VCO's.

What more do you want? - its cheap, readily available, easy to use,
recyclable, easy to get out for equipment maintenance, smells ok when
melted (better than modern chemicals) - need I say more?

Andrew VK3BFA
Andrew, do you know what the thermal conductivity of beeswax is?
Alan

Nope. Is it remotely relevant to this application?

Andrew VK3BFA

Andrew Mitz wrote:

"Larry Gagnon" wrote in message
newsan.2004.12.15.21.21.27.858623@fakeuniserve .com...


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


I have repaired a number of Epoxy Potted VCO modules by simply resoldering ALL of the PCB board connections !
The source of the problem is difference in the Coefficient of Expansion
between the Epoxy potting compound and the PCB and the solder
connections. Close inspection (under a microscope) will show that the
joints in question have been fractured by repeated thermal cycling. Hand
resoldering, rather than the original Wave-Soldering will produce a
much stronger bond between the component leads and the PC board and
reduce the problem.

Yukio YANO VE5YS

On 6 Sep 2005 22:16:36 -0700, Andrew VK3BFA wrote:
Andrew Mitz wrote:
Beeswax is exceptionally good for protection from an
ionic environment (salt water, human body).

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.

"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?

Had a Yaesu FT-470R 2m ssb/fm transceiver in recently for repair - VCO
was faulty. The module had been encapsulated in expoxy resin, and took
AGES to chip out with a fine wood chisel (and lots of swearing). Broke
a few components doing it, but could replace them so did. Pig of a job.

I consider this to be the definitive reason why beeswax is a better
potting material for VCO's.

What more do you want? - its cheap, readily available, easy to use,
recyclable, easy to get out for equipment maintenance, smells ok when
melted (better than modern chemicals) - need I say more?

I always have used paraffin -- way more 'solid' and takes more heat
to melt than 'normal' candle wax.
Maybe I was violating some law...
YMMV
Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
Pueblo, Colorado | @ | Jonesy | OS/2 __
38.24N 104.55W | config.com | DM78rf | SK

Andrew, do you know what the thermal conductivity of beeswax is?
Alan


Nope. Is it remotely relevant to this application?

Andrew VK3BFA

It could be. One problem with temperature compensation is that the
various components of an oscillator have differing thermal masses,
thermal conductivities and hence thermal time constants. So it helps to
have everything thermally connected so all component values change at
the same rate.
If beeswax conducts heat well, then potting the oscillator with it would
assist temperature stability.
Alan