From: "Tom Tishken KD4WOV" <kd4wov@earthlink.net>
To: rsgb_lf_group@blacksheep.org
Subject: RE: LF: Tesla Coil as an antenna
Date: Tue, 29 Jan 2002 15:13:31 -0500
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Yes, keeping the sparks from flying  is one major concern i was having. I
had a primary coil that resonated very well at 138 KHz, but I never finished
making a secondary coil. Other than a Large globe atop a large secondary
coil, has anyone else found a way to keep it from arcing?

  Second question, should we try to drive it with high voltage (400 to 1200
volts and very little current) or should we drive it with low voltage (12 to
24 volts and 10 to 40 amps). The primary coil I was using would withstand 12
volts and 30 amps, I cooked it when I went to 37 amps.

  Third question, For all you LF antenna guru's. should I use stranded or
solid copper, steel, or aluminum wire. I know each one has good and bad, but
what have you all had better luck with?

  I have thought about keeping the primary coil in mineral oil for heat
dissipation, any suggestions about cooling of the primary? What do you all
use to keep your LF antennas cool?

-----Original Message-----
From: majordom@post.thorcom.com [mailto:majordom@post.thorcom.com]On
Behalf Of James Moritz
Sent: Tuesday, January 29, 2002 11:05 AM
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: Tesla Coil as an antenna


At 09:14 29/01/2002 -0500, you wrote:
>Hello,
>   I have not experimented in a while with my partially built tesla coil,
but
>has anyone used their Tesla coil as an antenna for ELF or other Freqs? If
we
>try to use it for 137 KHz how do you determine ERP?
Dear Tom, LF group,

Well, occasionally I have inadvertently used my LF antenna as a Tesla coil
:-) But seriously, The Tesla coil is essentially a helical antenna (see
ON7YD's LF antenna web pages  http://www.qsl.net/on7yd/136ant.htm ). So if
it is several metres tall, and you can persuade it to resonate on 136kHz,
it might make a usable LFantenna. Of course, you would want to avoid the
discharges that occur in the normal Tesla coil mode of operation, since
these generate QRM and absorb lots of RF power.

Cheers, Jim Moritz
73 de M0BMU