[Milsurplus] Type 180 crystals

[C. Whitaker]

de WB2CPN
Hue, I think fixed plant transmitters
used a wider verity of crystal sockets
than smaller equipment.  Maybe it was
for propriety purposes.  The info about
hand made tubes came from the processes
of replacing filiments and damaged elements,
and then resealing the glass.  On those
envelopes with flat (?) bottoms the glass
would be lapped with great precision in
order to join the glass bead with minimum
heat applied to the glass.  I think it
was the Russians and Eastern Europeans
that speadheaded the technique.  Maybe
a WWII ham magazine would have more info.
73  Clete