[Hammarlund] Speaking of Tubes ...

[W7FE]

I'd vote for the 12AT7/12AU7/12AX7 family of dual triodes as one of the most used tube types ever produced. They've.been incorporated in literally hundreds of applications over the years as switches (think UNIVAC, ENIAC and Philbrick compiuter circuits), cathode followers, comparators, oscillators, amplifiers, etc. Indeed, they are still used in newly designed audio preamps and can be found in radios, TV's, and electronic gear of virtually.all types thru the years

I recall that the particular Army missile system I worked on back in the 60's had 512 12AT7's just in the control center van and many more in all manner  of circuits in the various radars, launchers, and test sets -- and that was just one  relatively low volume system, an ancestor of the current Patriot and Iron Dome missile systems. Just think of all of the receivers, transmitters, amplifierrs, tuners, etc., both military and commercial, produced over the last 60 years, nearly all of which incorporated at least several of the 12AT7 family of tubes.  

If that's not the most proudced tube type ever, I'd bet it's right up there with the leaders.

73 de Stu, W7FE
Henderson, NV

"Kenneth G. Gordon" <kgordon2006 at frontier.com> wrote:

>On 30 Sep 2014 at 22:55, Guido Santacana wrote:
>
>> What if... Solid state devices had not been invented back in the 50s. Tubes
>> would have evolved into ....... Sub sub miniature tubes?
>
>Probably. 
>
>I have always regarded the subminiature tubes first developed during WWII, 
>as an extreme example of what COULD be done with tubes.
>
>Lifetimes of 100,000 hours for instance.
>
>So, here are a couple of related questionss for all of you:
>
>1) Which is the single tube of which the greatest number were made, and, 2) 
>what was its main application?
>
>Ken W7EKB
>______________________________________________________________
>Hammarlund mailing list
>Home: http://mailman.qth.net/mailman/listinfo/hammarlund
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:Hammarlund at mailman.qth.net
>
>List Administrator: Duane Fischer, W8DBF
>** For Assistance: dfischer at usol.com **
>
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html