"Michael Black" wrote in message
news:alpine.LNX.2.02.1512021325170.11559@darkstar. example.org...
On Wed, 2 Dec 2015, whit3rd wrote:

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.
I dont' think anything much new got released after a certain point. But
those tubes did offer the chance to make equipment smaller, and certainly
in the early days of transistors, the tubes had better high frequency
response.

They didn't have any transistors in WW2 - but they needed a crude doppler
radar for proximity shells that could be fired out of an anti-aircraft gun.

AFAIK: they used what were basically ruggedised hearing aid valves potted in
wax to stop them bouncing about.