1 Mar
2010
1 Mar
'10
5:07 a.m.
Tony Duell wrote:
Doublers often were used in transformerless sets in the US, perhaps
almost always. ISTR seleniums with a gradual migration to solid state
diodes as they became available in the needed voltage ratings. At the
moment, I can't recall having seen vacuum tube diodes used in a TV
doubler, though I imagine there were instances of that. I still have a
little 14" B&W Motorola in the garage (with a bad CRT) that might not
have the doubler. If I ever find it again or the Sams for it I'll have
to check and see. Please keep in mind that I'm speaking from my
memories of TV repair in about the 1956 to 1960 area. Once I completed
college in 1960 my path led me to devices mostly containing those
mysterious devices with no filaments. :-)
Later,
Charlie C.
On Fri, Feb
26, 2010 at 2:26 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
I am suprised that voltage doubler PSUs (2 diodes, 2 capacitors) weren't
used in the States.
-tony
Ah, TV sets over here rarely had power
transformers at all... Every valved
monochrome TV Iv'e worked on... had a 300mA series string of valve heaters
and got the B+ line by half-wave rectifying the mains.
Sure, but your mains were
twice the voltage of our mains.