On Sep 24, 12:02 am, clare at snyder.on.ca wrote:
On 24 Sep 2007 01:10:00 GMT, (DoN. Nichols)
wrote:

I suspect that portable radios in the past (tube days) used F
cells more commonly than today, which is why the 6V lantern battery was
designed to be just the right size to hold four F cells.

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.

No, doesn't make sense. A battery for a radio with a power rectifier
tube? That's like saying a gas cap for an electric car.

"A" is filament battery, "B" is B+ (plate) battery, "C" is bias
battery (although many radios were cleverly designed to not need a
bias battery).

Most commonly the "A" battery was a single lead-acid storage cell. You
can tell because the tubes were rated for 2.0V filaments (a lead-acid
cell under discharge is 1.9 to 2.0V).

Do not confuse "A", "B", "C" batteries with industry-standard cell
sizes. Battery is not the same as cell!

The F cell is just two sizes larger than the D cell. :-).

Tim.