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On Mon, 31 Dec 2018 11:38:54 -0800, Big Bad Bob
wrote:

On 12/27/18 19:11, wrote:
The most important tubes ever made.....

12AX7
12AU7
12AT7

6V6
6L6

etc.

well maybe for audio but you're forgetting why tubes were more or less
used/invented in the first place, to receive radio signals, and the
audio amplifier portion was just a part of that.

For radios the pentagrid converter tube comes to mind as one of the most
universally used tubes ever for AM radio, in home sets and cars in
particular. For FM sets there are a number of VHF RF amplifiers.

Then there's the sharp cutoff pentode, which is ideal for an IF strip
with high gain, relatively low noise, and AGC.

And don't forget the CRT. For that one, there was a model that nearly
eveything used for about a decade [higher end sets anyway], a 25 inch
diagonal square color tube from RCA [I forget the number].

And there are many specialized tubes for microwave oscillation and
amplification that are STILL USED on satellites, last I heard.

And that magnetron in your home microwave. That's right, it's a tube.
Invented in the late 30's, for use in RADAR systems.

So yeah tube audio is one usage, and maybe those tube numbers are some
of the most important in the audio world [especially guitar amplifiers].
But overall, I think some of the others deserve a mention.


/me has even conceived of a 'graviton generator' using something similar
to a magnetron filed with Xe gas. You'd need tremendous power to make
anything useful out of it, but the resonant cavities [in theory] would
emit gravitons when spinning a heavy gas in tight little circles like
that...

so yeah, it's likely that tube tech isn't going away any time soon, and
will continue to improve over time. In space this may become even MORE
important, depending.

Yea, I know microwaves have tubes, and I did consider CRTs on the list
but I was mostly thinking in terms of home radios and audio amps.

Please add some tube numbers for those small tubes you mentioned above.
I would like to see what you and others have to say.

I also neglected to include some of the major transmitting tubes, mostly
because I dont know the numbers. Although I do know the 807 was used
quite a lot in the early days. That tube became the 6L6 without the
plate on the cap. But the 807 also worked great for audio.