[AMRadio] 810's

Rick Brashear rickbras at airmail.net
Fri Aug 24 10:49:16 EDT 2007

Thanks Todd.  I think I'll give JB Weld a shot.  I'm not real sure the tube
(810) has much life in it, so I won't spend too much time and money on it.
I'm sure you're right, the expansion and shrinking will be a big factor in
how well it holds.  Since it is used widely on engine blocks I guess that
would speak well of its ability to withstand the variations pretty well.

Thanks again to all for your responses and advice.


Rick, it's been a while for me, but the main issue I recall was
expansion/contraction, with the envelope heating or cooling at a rate
that the glue couldn't match, resulting in cracked tube or broken
seal. It's been a long time though, so I really don't recall the

JB Weld is used on engines and other high temp applications as
mentioned, so it would probably be fine. I run 810s as modulators and
they do get hot, but I doubt it would be an issue.

Sometime somewhere, YEARS ago, I had the formula used by RCA for this
purpose. Maybe I'll find it during the move?

Good luck -

~ Todd,  KA1KAQ

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