Fw: GB> 136 kHz Transmitter and antenna system.

[Randy Mays]

Hi,

    I received this from a friend in the Midwest.

From: <Zadacha@aol.com>
To:
Sent: Wednesday, May 02, 2001 9:01 PM
Subject: GB> 136 kHz Transmitter and antenna system.


> Ken,
>
>     You're right, that was very interesting.  VLF is the "last frontier" I
> suppose now.
>
> Years ago, before the "net" I used to correspond with Dr. Larry Jack, a
> brilliant professor at the University of Maryland.  He was doing a lot of
VLF
> research for, well, I don't really know for whom, but he was doing it on a
> part V license in our own 1750 meter band.
>
>     He used up to 5 kW in his experiments, but found 15 to 30 watts to be
> sufficient, and a whole lot less dangerous to be around.  He was using a
40
> foot vertical composed of two 20 foot sections of 2 inch copper pipe
silver
> soldered together, end to end and guyed.  On the top of this he had a 1/2
> wave loading coil, being 4 feet of 4 inch PVC pipe wound with almost 2
> thousand turns of #26 wire, and the whole thing was topped by a giant ring
> capacity-hat made from 1/2 inch copper pipe and looking like a 6 foot
wagon
> wheel.
>
>     Being a half wave, top loaded vertical, it could be fed with a high
> impedance match, much like a tesal coil.  He was getting hundreds of miles
in
> his signal reports on the very few watts he decided was the best.  He
tried,
> for the most part to stay within Part 15 so it would appeal to other
> "LowFers" and at the same time report his research to the Feds for their
> proposed GWYN program, which is now almost passe.
>
>     He used an existing 6 inch well casing in his yard, for the ground and
> mounted his transmitter directly on it, with a piece of copper strap going
> over to the antenna base, about a foot away.
>
>     I don't know the status of the Part V licenses, but you could get them
> for almost any ligitimate experimental purpose, but you had to report your
> findings to the FCC.  Perahps someone knows the current status of this
neat
> license.
>
> Roy
>
>