23 Apr
2024
23 Apr
'24
12:35 a.m.
On Apr 22, 2024, at 7:03 PM, Chuck Guzis via cctalk
<cctalk(a)classiccmp.org> wrote:
On 4/22/24 14:34, dwight via cctalk wrote:
What about the coincidence that a lot of today's logic runs on 3.3 volts, just about
the same as the first generation of IC logic (RTL).
For those that don't know what a UV(UX)201
was, it was most commonly used for audio amplification in early battery powered radios.
These used a lot of filament current, not like later miniature tubes.
They had a UV(UX)200 tube for RF detections that worked better as a grid leak detector, I
think because of less cutoff voltage needed as a detector.
The A series used a better getter and lower current filament ( one or both? ) but still
used a lot of filament current.
I've long considered it to be an interesting coincidence that the
filament voltage of the UV201 was 5V, just like much later TTL logic. Folks don't recall that RCA was formed to get
around a patent issue on
the basic idea of a triode.
Interesting!
paul