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Howdy, Folks !



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From:  Bert Hickman [SMTP:bert.hickman-at-aquila-dot-com]
Sent:  Tuesday, August 11, 1998 7:03 AM
To:  Tesla List
Subject:  Re: Howdy, Folks !

William,

Welcome aboard! BTW, I tried accessing the site - the website address
should instead be http://www.altair-dot-org/tesla.htm (looks like the ".htm"
may have gotten truncated). 

Your best bet, because of the relatively low power levels and SW caps,
should be the 8" coilform, and you may even have some problem driving
that size properly with anything less than 900-1400 watts. 

The NST that acts differently may be internally constructed a bit
differently - some transformers may be constructed with a third winding
and an internal power factor correction (PFC) capacitor. This is done 
so that some of the transformer's input inductance is cancelled,
bringing the mains input voltage and current closer in phase. This 
improves the overall power factor for the user, and can be important for
a large installation since it reduces the peak current drawn from the
mains. If the odd transformer does have internal power factor
correction, the faceplate should provide some indication - I believe
some vendors use a P suffix on the model number. Or, your transformer
could simply be partially shorted. In any event, if you can't phase it
properly with the rest, it can't be connected in parallel with them. 

Don't know how well the secondary would work as a beacon - I'd suspect
rather poorly, since when at 1/4 wave resonance it may be a rather poor
antenna at Fo due to it's rather short physical length versus the
free-space 1/4 wave wavelength at 184 kHz (>1300 feet). 
 
-- Bert --

Tesla List wrote:
> 
> ----------
> From:  Payne, Will E [SMTP:will.e.payne-at-lmco-dot-com]
> Sent:  Monday, August 10, 1998 9:43 PM
> To:  'Tesla List'
> Subject:  Howdy, Folks !
> 
> New member here, built a Tcoil in college. My modestly sucessful original
> design, plus a big 'un by a friend, is at http://www.altair-dot-org/tesla/ for
> reference.  Thinking about coiling up another one, but before proceeding
> farther, would welcome comments from all you experienced builders out there
> :
> 
> Have got two forms at my disposal, first is white PVC pipe 8 in x 6 ft with
> 1/2 in walls, second is green fiberglass 12 in dia x 4 ft, with 1/8 in
> walls.  Have plenty of #20 wire, a variac, several 450 VA neon xfmrs, and a
> stovepipe toroid about 22x8 in.
> 
> Which form ought I use ?  Is 450 VA enuff to drive a coil this size ?
> 
> Plan to start with saltwater caps and a fixed gap.  Comments ?
> 
> Tried parallel connecting 3 identical neon xfmrs all same make and model,
> but one acts almost as if 90 deg out of phase with the others.  What gives ?
> 
> Might try to use the secondary for an output of my LF radio beacon.  Anyone
> tried this ?  (any lowfers out there I am YWK on 184.320 kHz CW, grid
> EM74oa)
> 
> Thanks for your comments !
> Altair
> 
> William E. Payne
> 275 Oak Hills Dr
> Dallas, GA    30132
> 
> 770-494-1104 (day)
> 
> altair-at-altair-dot-org
> www.altair-dot-org