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Re: Filament voltages

Original poster: "Gregory Hunter by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ghunter31014-at-yahoo-dot-com>

Your filament transformer should develop 10vac
open-circuit. For example a 120V:10V transformer would
be just fine. Yes, the voltage will drop a bit under
load, but 10A across the filament is the important
part. BTW, I used an old MOT to make a filament xfmer
for an 833A. I used a hacksaw to remove the secondary
coil, leaving the 120v primary intact. I wound it with
10AWG stranded until I got 10vac output. I think I had
about 12 turns. I used regular THHN wire and bound it
in place with cable ties. It can light up an 833A all
day without even breaking a sweat.



--- Tesla list <tesla-at-pupman-dot-com> wrote:
> Original poster: "Sundog by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <sundog-at-timeship-dot-net>
> Hi All,
>   A dumb question that I *should* know, but can't
> find the answer to.   The 
> 833's want 10v10A filament supply.  Do I adjust the
> filament voltage before 
> or after I load up the transformer with the tubes? 
> The filament is just a 
> big resistor, so there is significant voltage drop
> across it.  Should I 
> read 10v on the tranny or on the filament leads?
> Shad G3-1203