{Collins} Centron 811A

[john nelson <solarelectricjohn@xxxxxxxxx>]

I have 3 sets of 811A from NB but never had an issue like some have. I have
fixed a few rare tubes in the past that had plate caps that came loose.
Talking with a friend that was a chemist he said that the silicon based
adhesive used in old tubes needed to be heated to set the adhesive and in
cases of some they just were not cured long enough and over decades the
adhesive just broke down. Now as many of you know when restoring old radio
equipment sometimes we have to reinvent past engineering and do it our
self's. Their is a company called Flexbar that makes several products that
bond glass and metal from -350 to 2200 deg F it is about $30.00 also there
is a half dozen venders on fleabag that sell similar products. I have never
had an issue after rebounding old plate caps back on. So let me know if you
have (NEW) old Centron 811A's that have loose caps and I will give you five
bucks apiece for them and even pay the shipping.

John W0XAZ