On Tuesday, December 1, 2015 at 5:23:03 PM UTC-8, Michael Black wrote:
On Tue, 1 Dec 2015, Ian Field wrote:


Apparently there was a time that most remote garage door openers had a
Nuvistor of some description.

I've never heard of that, but it's possible. There were those subminiature
tubes (the leads were generally laid out in parallel with each other, and
the leads were relatively low gauge wire) seen in hearing aids and some
portable radios.

I've heard those called 'pencil tubes'; the ones in hybrid walkie-talkies
(for the transmitter) didn't get replaced with semiconductors until mid-to-late
seventies.
Nuvistors were ceramic-metal base, metal envelope tubes, very rugged,
and much less microphonic than other vacuum tubes. There was a long
period when they were the best fast-slewing amplifiers around, and for
HV handling (like electrostatic deflection in CRTs) very hard to replace
with silicon.