Message-ID: <007301c0981a$8cb5cbf0$0a00a8c0@ThreeLakes.ca>
From: "Larry Kayser" <kayser@sympatico.ca>
To: rsgb_lf_group@blacksheep.org
References: <000d01c09803$a1e46e80$2d9b883e@lvm>
Subject: LF: Insulators for probe antenna
Date: Fri, 16 Feb 2001 08:15:29 -0500
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Sender: <majordom@post.thorcom.com>

New Subject

Greetings All:

I am preparing to have three separate LF antennas at my permanent home for
the next LF season.  One antenna I want to try is a short probe antenna, a 5
ft piece of copper pipe.  The impedance needed is in the multi megohms,
currently I am using a large sheet (30 cm square) of clear plastic known
commercially as LEXAN by General Electric.  My sense is that I might do
better, the issue is what would be better as an insulator for mounting the
pipe on?

I have available locally, and very expensive, some ceramic standoff
insulators with metal fixtures at both ends.  These are designed for service
inside older equipment and may not work well outside in the open air.

Some discussion on the issues around insulator design for highest working
impedance in this service will be greatly appreciated.  The copper pipe is
connected virtually directly to the Gate of a FET.  Yes, I use a ceramic
socket for the FET and I buy the FET's very cheap and in large quantities as
lightning fuses even with high speed diode protection devices hi.

Larry
VA3LK