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Re: HV wire



Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

http://home.earthlink-dot-net/~jimlux/hv/hvwire.htm has some info...

There are several basic approaches:  1) Ignore the insulation and support
the wire on insulating standoffs and protect it from accidental contact. 2)
Use HV wire with insulation rated for the operating voltage. 3) Improvise by
using something beyond rated specs, or add insulation.

For #1, almost anything will do, although larger in diameter reduces loss.
AWG#10 or AWG#12 is probably ok, AWG#6 is readily available bare and is
stiff enough that you can form it to shapes and support on standoffs.  For
that matter, thin wall copper tubing would also work, since the middle of
the wire isn't doing anything anyway, what with skin effect.  (For the tank
loop only... the HV coming from the NST doesn't have RF, so all it has to do
is carry the 60 mA current.... AWG #20 is probably good enough there,
although corona will kill you for such small wire.

For #2, you can use solid core sparkplug wire (make sure it isn't
suppressor, or some fancy spiral wound "go-fast" wire.. just tinned copper
core).  You can get real silicone insulated HV wire surplus, but it's pretty
expensive (> $.50/ft).  It's nice and flexible though.  Neon Signs are wired
with what is called GTO-15 wire, which has a polyethylene insulation, and is
fairly inexpensive, if you find a source that will sell by the foot (unless
you want a 500 foot box).

Or, you can use the inside of  RG-8 (RG-213) coax, which is AWG #13. (This
is the coax that is about .405" in diameter). Don't use foam insulated coax!
I use lots of coax, with the shield grounded, but there is some opinion that
the capacitance between ground and HV causes problems. For what it's worth
RG-8 is rated at 5kV AC RMS for RF.  However, that includes a substantial
margin for voltage peaks due to mismatch.  As a practical matter, it's
probably good to well over 30 kV, especially if the shield is left on and
grounded, so the field in the dielectric is uniform.


You can take ordinary wire and thread it through insulating tubing.
Polyethylene tubing is readily available and cheap (it's that milky white
stuff they use for plumbing refrigerator icemakers).  Check the wall
thickness! PE is probably good for (conservatively) 250 kV/inch thickness,
so 1/8" wall is around 30kV (safely).  Vinyl tubing (e.g Tygon) is another
possibility, but I don't know how good an insulator vinyl is.




----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, January 11, 2002 7:40 PM
Subject: HV wire


> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Kidd6488-at-aol-dot-com>
>
> Quick question.
>
> 12/60 trannie, will be TSG. What guage wire recommend for HV side?
>
> also, what types of HV wire you guys use?
>
> ---------------------------------------
> Jonathon Reinhart
> hot-streamer-dot-com/jonathon
>
>