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Howdy, Folks !
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From: Thomas McGahee [SMTP:tom_mcgahee-at-sigmais-dot-com]
Sent: Tuesday, August 11, 1998 10:27 AM
To: Tesla List
Subject: Re: Howdy, Folks !
Will,
Welcome aboard!
Comments interspersed below.
Fr. Tom McGahee
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> From: Tesla List <tesla-at-pupman-dot-com>
> To: 'Tesla List' <tesla-at-pupman-dot-com>
> Subject: Howdy, Folks !
> Date: Tuesday, August 11, 1998 12:17 AM
>
>
> ----------
> 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.
Try to keep your Height to Diameter (H/D) ratio 4 or lower. A ratio of
about 3 works well for the larger diameter forms.
The larger diameter forms can handle more power. The thing is, they also
require more power. The three 450 VA xfrmrs will give you almost 1.5 KVA,
so you could get by with the 12" diameter form OK, though more power
would be better.
>
> 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 ?
Make polyethylene capacitors if at all possible. Rolled or flat will
do, and oil-immerse them in transformer oil. There are excellent textx
on making these things in the Tesla archives. They make MUCH better
caps than the salwater units. But if saltwater caps is all you can swing
at the moment, then go for it.
>
> 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 ?
>
These transformers, even though same make and model, are not necessarily
phased the same. For their intended use as neon sign transformers the
designers were not concerned about primary/secondary phasing. Determine
which is the offending xfrmr, and reverse the PRIMARY leads on that
unit and you should be in business. May I suggest that you use paint
to mark a relative phase indicator on the primary connections? This way in
the future you won't have to try and remember what is what. Mark EACH
transformer primary.
>
> 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
>
>
Hope this helps.
Fr. Tom McGahee