On 4/22/24 14:34, dwight via cctalk wrote: > 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. --Chuck
