beeswax in an oscillator compartment
 

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.

"Larry Gagnon" wrote in message
om...
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


Larry -

Beeswax and encapsulation seemed to be the fad for the Japanese mfg. in the
early 1980s. I have heard various reasons, but mobile operation (with
potential bouncing and jarring) is often mentioned.
Kenwood amateur gear had some noted PLL problems with their encapsulation
materials of that period -- although they were not the only mfg. using this
method.

I am curious to know the age of the transceiver and mfg.

Greg
w9gb

"Larry Gagnon" wrote in message
om...
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.

Beeswax has been used for securing the windings on toroids.

73, Leon

Beeswax has been used for securing the windings on toroids.

According to my boss in the late '60s and
early '70s,W.T.G. Glasspool (would you
guess he was British?), beeswax was widely
used in the past to secure coil windings,
seal slugs in the cores of forms and
transformers, etc.. Apparently it doesn't
reduce the "Q" too much, and was readily
available in those days.

73, John - K6QQ

On Wed, 15 Dec 2004 13:21:28 -0800, Larry Gagnon
wrote:

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

Go ahead and remelt it. We always did when I used to work in Midland's Service
department back in the 70's. Never caused a problem.

Hi,

According to my boss in the late '60s and
early '70s,W.T.G. Glasspool (would you
guess he was British?), beeswax was widely
used in the past to secure coil windings,
seal slugs in the cores of forms and
transformers, etc.. Apparently it doesn't
reduce the "Q" too much, and was readily
available in those days.

73, John - K6QQ

I purchased some here in the UK from a local craft shop quite
recently. It is an excellent material for holding things together
as long as the temperature doesn't get too high and IMHO makes a
neater job than hot-melt for holding small items onto a PCB. The
trick is to keep an old iron bit especially for the job (and also
for starting holes in plastic boxes.) The stuff I got is in the
form of small beads and so very easily handled with a pin.

The wax in that VCO, BTW, is anti-microphonic in purpose and
definitely should be re-melted. This is particularly important if
the loudspeaker is in the same cabinet with the radio.


Cheers - Joe, G3LLV

"Larry Gagnon" wrote in message
om...
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

--
Beeswax goes back the the 1930s USA designed radios too.
In common radio design use since then.
It is excellent as it has a high melting point (for waxes).
Just put some it back on, it keeps the coils/wires stationary.
You should only need a line on both sides of the coil.

In article , "Chuckie"
writes:

"Larry Gagnon" wrote in message
news:pan.2004.12.15.21.21.27.858623@fakeuniserve. com...
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

--
Beeswax goes back the the 1930s USA designed radios too.
In common radio design use since then.
It is excellent as it has a high melting point (for waxes).
Just put some it back on, it keeps the coils/wires stationary.
You should only need a line on both sides of the coil.

Quite true on old-time radio production, but primarily for the
lower-cost "consumer" type models.

The wax isn't from bees, but rather from other sources and is
usually called "ceresin wax." Pours easily when hot, stays hot
enough for a quick brushing-on. Unfortunately, hot spots in old
tube/valve equipment lets the wax soften and it sometimes dribbles
off and quits holding what it was supposed to hold.

O-T story: Back in 1956 when I was new to WREX-TV and on
midnight maintenance shift, I was supposed to align the air
monitor scope that sampled the transmitter output signal. The
video response was way off judging by the sync signal appearance.
Cause was the peaking coils of the internal tube video amplifier. An
hour spent with a video sweep generator and a hot iron brought the
peaking coils (pie-wound inductors sliding on 1 Watt resistor bodies)
into a good, flat video response. Early day shift complained long and
loud about "the air monitor doesn't work!" It showed the correct
waveform, not the one they were used to! :-) [nobody had been able
to fix it before and all it took was to move the coils slightly to adjust
their inductance]

There's nothing special about the wax. It was a convenience to use
in production, quick, easy-to-use and cheap. To do a good hold on
things like inductors, I would recommend the "spar varnish" kind of
varnish (made from pretroleum distilates, not the urethane type). One
example of that is McCloskey "Gym Seal" intended for hard-use
floor finishing and found in lumber yards and do-it-yourself stores.
Varnish needs to cure overnight to be effective, doesn't drop Q any
more than the polystyrene "Q Dope" (which will lose its holding power
because of moisture breaking the bond to the work), and holds on
infinitum (also known as at least 30 years based on my experience).

"Avery Fineman" wrote in message
...
In article , "Chuckie"
writes:

"Larry Gagnon" wrote in message
news:pan.2004.12.15.21.21.27.858623@fakeuniserve. com...
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

--
Beeswax goes back the the 1930s USA designed radios too.
In common radio design use since then.
It is excellent as it has a high melting point (for waxes).
Just put some it back on, it keeps the coils/wires stationary.
You should only need a line on both sides of the coil.

Quite true on old-time radio production, but primarily for the
lower-cost "consumer" type models.

The wax isn't from bees, but rather from other sources and is
usually called "ceresin wax." Pours easily when hot, stays hot
enough for a quick brushing-on. Unfortunately, hot spots in old
tube/valve equipment lets the wax soften and it sometimes dribbles
off and quits holding what it was supposed to hold.

O-T story: Back in 1956 when I was new to WREX-TV and on
midnight maintenance shift, I was supposed to align the air
monitor scope that sampled the transmitter output signal. The
video response was way off judging by the sync signal appearance.
Cause was the peaking coils of the internal tube video amplifier. An
hour spent with a video sweep generator and a hot iron brought the
peaking coils (pie-wound inductors sliding on 1 Watt resistor bodies)
into a good, flat video response. Early day shift complained long and
loud about "the air monitor doesn't work!" It showed the correct
waveform, not the one they were used to! :-) [nobody had been able
to fix it before and all it took was to move the coils slightly to
adjust
their inductance]

There's nothing special about the wax. It was a convenience to use
in production, quick, easy-to-use and cheap. To do a good hold on
things like inductors, I would recommend the "spar varnish" kind of
varnish (made from pretroleum distilates, not the urethane type). One
example of that is McCloskey "Gym Seal" intended for hard-use
floor finishing and found in lumber yards and do-it-yourself stores.
Varnish needs to cure overnight to be effective, doesn't drop Q any
more than the polystyrene "Q Dope" (which will lose its holding power
because of moisture breaking the bond to the work), and holds on
infinitum (also known as at least 30 years based on my experience).



Remember "fish-paper"? used that in a early 1980 moto radio design.
I know the type of wax you are talking about, harder and a little darker
than beeswax.

Actually, the beeswax is a natural byproduct of 30 hertz oscillators.
Always wear gloves before opening!

:)

The Eternal Squire

Chuckie wrote:
"Larry Gagnon" wrote in message
om...

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

--

Beeswax goes back the the 1930s USA designed radios too.
In common radio design use since then.
It is excellent as it has a high melting point (for waxes).
Just put some it back on, it keeps the coils/wires stationary.
You should only need a line on both sides of the coil.

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
om...
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
om...
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
om...
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
news:pan.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
om...
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

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

http://www.fao.org/docrep/w0076e/w0076e12.htm
Bruno
Thanks (or is it Danke)
Very informative.
Alan

In article ,
Alan Peake wrote:

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



The beeswax also stabilizes the components so they don't vibrate for
whatever reason. Vibrations can induce changes in values for susceptible
components resulting in modulation of the output frequency.

Al

Yukio YANO wrote:
Andrew Mitz wrote:

"Larry Gagnon" wrote in message
news:pan.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

Thats a good point, Yukio - BUT...... its usually a major job to get to
the bottom of the vco module anyway - (it was in the 480R I did) - to
just resolder, then re-assemble into the board would have been easier,
but it would also have meant another load of massive thermal stress on
everything if it DIDNT work, or failed again. Thats why I did the
chisel out and replace job.

I did manage to establish (by using a steel probe and poking) it was
one of the epoxy potted on board transistors - I wonder if the two
epoxy mixes were pulling and pushing each other apart?

Interesting speculation - I just fix the things based on 20 years of
stuffing around, burning fingers, and cursing pig ignorant engineers
who design radios without thought of serviceability!

And if you have the right iron (a big one) and can solder well, its not
really a problem to do - just tedious, but worth it for a long term
fix.

Andrew VK3BFA.

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

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

Very informative.

http://www.kayelaby.npl.co.uk/genera...2_3/2_3_7.html is also
interesting, especially if you follow the link to the polymers page at
http://www.kayelaby.npl.co.uk/chemis..._1.html#3_11_1

It looks as if beeswax and paraffin both have thermal conductivities
of about 0.25 ( when measured in W / (m K) ), and that epoxy cast
resins are in the range of 0.17 - 0.21.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Alan Peake wrote:

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. . .

This is one of several reasons that the best approach in designing an
oscillator -- or any other temperature sensitive circuit -- is to use
components that each have as small a temperature coefficient as
possible. That is, first minimize the inherent drift. Then, if you must,
compensate what drift remains.

Roy Lewallen