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Re: Filament voltages

Original poster: "sundog by way of Terry Fritz <twftesla-at-qwest-dot-net>" <sundog-at-timeship-dot-net>

I tried using a MOT with the secondary chiseled off and 12ga THHN (15 turns 
I think), and while it worked fine for 1 or 2 833's, running 4 tubes with 
no plate voltage, the transformer got scorching hot, and with a 
considerable load, the insulation on the wires melted until it shorted the 
inner turns of the secondary.  I went with the 1/8" tubing because I don't 
want a problem with heat, period. There's plenty of space on the core for 
it, and room for a new primary if I need to wind one.  You can see pictures at


Once the torturous hell I call "work" is done with, I'll try to get the 
fil. voltage corrected on the Quad833 and see how the system runs then.

Shad G3-1203

At 10:01 AM 5/1/02, you wrote:
>Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
>Tesla list wrote:
> > Original poster: "sundog by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> ><sundog-at-timeship-dot-net>
> > Hi Dave,
> > The tranny for the Quad 833 is a separate tranny than the
> >plate tranny.  It's wound with 1/8" tubing on an old NST core.
> >Unloaded I get 10.2v on it, loaded that drops to around 7v
> >(pushing 4 tubes).  Do I need to correct the fully-heated
> >filament voltage to 10v, or let it sit at 7v?
>         I would certainly correct it.  cf someone else's
>         quite thorough posting on the problems with
>         underpowering the filaments.
>         As to the wiring (another other post) I can't see
>         #8 for 10 Amps for short runs.  #14 should be fine,
>         even #12 would be generous.
>         best
>         dwp

Shad (Sundog)
G-3 #1203
"Ever stop to think, and forget to start again?"