Date: Mon, 26 Jul 1999 19:23:49 -0400
From: "Prof R. Jennison" <boffin1@compuserve.com>
Subject: Re: LF: Ground systems
To: rsgb_lf_group@blacksheep.org
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Just a minor comment on this much discussed topic. 
A few years ago, when experimenting with toroidal antennas on top band, I
ran into the same problem.  The local field from a toroid is entirely
electric and so the effect of the lossy earth was very severe especially in
the immediate vicinity of the antenna.  After a bit of head scratching I
isolated the output circuit from all local earths and used a counterpoise
consisting of a single wire about 50cm above the ground terminating in a
metal plate about 1 metre square, insulated at the same height. I am still
using it.
        Some of you may have heard my toroid on top band and will know how
well it works but if I connect the metal plate to ground the signal drops
by at least three or four S points.  The major losses usually occur in the
immediate vicinity of the antenna, the propagation loss further away is
still a problem but is less severe than that in the primary launching
system.

        Now I must sadly give notice that I will have to resign from this
net in the very near future.  It was wonderful when the group was small but
the traffic has grown so much that I cannot keep pace with my normal email
and I regret that it must take priority.

73 to you all,
Roger, G2AJV.