Charles said:
collectible.
Laughing. Seleniums went out of the picture long before tubes.
I have been working on color TVs since 1955 when I was doing some
college work on color prototype sets, even before the RCA CTC-1 came
out. To the best of my knowledge, no color set has ever been
manufactured in the USA using selenium rectifiers. The current levels
were too high and the selenium rectifiers got so hot that they were
relegated to mostly B+W sets and to automobile battery chargers where
they tended to be used with ventilation. The very early RCA - CTC-1
vintage sets used multiple 5U4s.
One early CBS prototype set, non-rotating wheel, built right after the
RCA NTSC format was approved, was a 2-cabinet affair. One cabinet was
just for the power supplies, the other cabinet used a round 16" metal
picture tube with a 12" flat color screen mounted inside the metal
tube. It took days to get the set purity and convergence set up, and
you didn't dare move the set once it was set up because the set was so
sensitive. This was at the University of Florida - Gainesville. I
graduated in 1957, and don't know what happened to that old CBS set.
It generated enough heat that we couldn't run it more than a couple of
hours except in the winter. No air-conditioning in the labs back in
those ancient days.
H. R. (Bob) Hofmann