I've never seen or heard of a steel 6SN7 and I started with tubes in the
early fifties. Now you have me wondering about metal tubes and except
for 6L6 most were real popular in car radios and 5 tube ac dc, also
military. Does anyone recall the first metal tube, who made it, why and
what they touted as their advantage other than it wouldn't break if
dropped. I also recall a real hi power amp being made with 6L6s that
were cooled by them hanging udside down from the chassis in a bowl of
water and others immersed them in oil.


--

73
Hank WD5JFR
"Theo" wrote in message
...
Regarding the "all metal" tubes series by RCA,
can anyone tell me if there was ever a metal version
of the 6SN7?
I cannot find any reference on the web.
Any help would be greatly appreciated.