Small tubes were popular in Hand Transceivers and all
sorts of stuff. Battery radios had them. Typically they
drew lower current on the filaments (heaters) and had them
on one battery. B+ was on another battery.

Tubes are on the upswing and there are a number of makers
for high end audio and high end power amps for transmitters.

I have a number of various tubes here. Some monsters that Iggy
would use or Gunner.

Martin

On 8/19/2015 1:13 PM, wrote:
On Wed, 19 Aug 2015 08:39:36 -0700, Larry Jaques
wrote:

On Tue, 18 Aug 2015 10:24:47 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Larry Jaques fired this volley in
:

It seems
that DARPA is hot for vacuum tubes.


Without even reading it, I can understand why. Tubes are VERY immune to
EMF damage, while semiconductors seem to just belly-up and die at the least
excuse.

Good point. I hadn't thought about it from that aspect. Some muzzy
moron is surely going to set off an EMP bomb around the world
somewhere soon, so the quicker we find ways around it, the better. "We
live in 800AD, and so should you."
I was looking at some kits for making small pre-amps or amps for MP3
players that use very small tubes. I don't know much about how tubes
work. I know the basics but I don't know how the actual size of the
tube internals and their proximity to the other elements inside the
tube affects the operation of the tube. I imagine that today with
modern automation equipment that tubes could be made very small
indeed. Whether the tubes would operate the same as larger ones I have
no idea about but would like to know. I have seen pictures of devices
made and used in WWII that contained very small tubes that were used
in anti-aircraft shells to iniate the explosion when the shell was
close enough to an airplane. These tubes were essentially hand made
and even though tubes seem to me to be delicate these had to be made
to survive the acceleration of the anti-aircraft shell when fired from
a cannon.
Eric