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Ohm's law



Seems to me that tube filaments or , for that matter, every lightbulb and
every
appliance in the house when connected in parallel must be operated at its
RATED
voltage. All house wiring and indeed our entire power system is wired in
parallel or
else a light burning-out in my barn would cut out everthing connected to the
same
pole transformer.The great all-American five table radios had a series
filament string that added up to around 115V. Transformerless. Parallel
filament strings must be transformer supplied. The 6.3V tubes are usually
0.15-0.30A ea. Ten tubes in parallel
need 6.3V at each tube, the current will be 1.5-3.0A. High amperage filaments
as
with 833A's or 304TL's must always be operated with a variac. And it was
always
good design practice to derate the filament voltage 10-15%. Try type 10 tubes
or
the larger triodes for class A amps. I need plans for a center-fed TC.
 
zeke