Message-ID: <002101c1b3a9$20325920$854101d5@dave>
From: "Dave Sergeant" <dsergeant@connectfree.co.uk>
To: rsgb_lf_group@blacksheep.org
References: <120.b40e402.299996b0@aol.com>
Subject: Re: LF: Loop questions
Date: Tue, 12 Feb 2002 08:56:16 -0000
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>From Dave G3YMC

Clearly the use of large transmitting loops is outside the terms of the lowfer
licence in the US.  However use of a receive type loop with many turns of thinish
wire (litz or not) for transmitting is not the way to go.  To get a signal in the air
requires a large single (or at most two) turn loop with thick wire.  I have used this
technique to some success on 136 as many of you will know, and my website details my
experiences.  The aim is the same as with any transmit antenna - to get the resistive
losses as low as possible related to the radiation resistance.  For this I use 30A
speaker cable and the resistance of my 33m circumference single turn loop is 0.65
ohms.  Loop current has been measured as 8A at 35W, they are not high impedance
devices!  And matching to the feeder must be at the feedpoint to eliminate resistive
losses in the feeder which will be very significant.

See my site for more details.

73s Dave G3YMC
dsergeant@iee.org
dsergeant@btinternet.com
http://www.dsergeant.btinternet.co.uk