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, 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

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

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