On Mon, 24 Sep 2007 17:43:24 -0700, "
wrote:

On Sep 24, 5:02 am, clare at snyder.on.ca wrote:


The "F" designation was for "F"ilament use. Lots of old batteries had
1.5 volt filaments in the rectifier tubes, so you had an "A", a "B"
and an "F" battery.

Now you are pulling our legs. You have a " B " battery for plate
voltage and just why do you have a rectifier tube?

The confusion is that there were A , B and C batteries for filaments,
plate voltage , and grid bias. But then there is also AAA, AA, C, D,
and F cells where the letter designates the size. I can't readily
find any source for the size designations, but it must be in some NEMA
standard.

Dan

Well, I've worked on an old battery set that, like a car radio of the
time, had a multivibrator to make the high plate voltages from a lower
battery voltage. IIRC the main battery was 12 volts. Most of the
"valves" or vacuum tubes ran on either 12 volts or six (2 in series)
but the rectifier has a 1 or 2 volt filament. It used an "ignition"
battery - one of those that used to run doorbells, fencers, and
battery ignitions on some stationary engines years ago. It was called
the "F"ilament battery. I think it was some sort of "farm" radio.

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