From: WarmSpgs@aol.com
Message-ID: <51.264fe513.2ae9ba52@aol.com>
Date: Thu, 24 Oct 2002 17:04:18 EDT
To: rsgb_lf_group@blacksheep.org
MIME-Version: 1.0
Subject: Re: LF: alternative antenna for 136kHz
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Hi Rik,

Looks to me as if the net result is simply going to be a small loop in series 
with a series-resonant circuit.

If antenna dimensions are an appreciable fraction of a wavelength, lumped 
reactances will start to affect the current distribution within a loop (or 
its variant, the line antenna) and thus affect its radiating properties.  For 
an amateur-size loop, however,  the current will be of the same magnitude and 
direction all the way around, even with the reactances present.

In this design, it is true that there will be high voltages across the 
reactive components.  But since it is accelerated units of charge which emit 
electromagnetic waves, merely having high electric fields present that 
contribute nothing to current in the antenna means only that there is 
increased risk of loss due to surrounding objects.  And, it will be necessary 
to closely watch the Q of the coil, just as with a short vertical antenna.  
In a sense, such an antenna may represent the worst of both worlds (loop and 
monopole).

Still, I don't mean to discourage anyone from trying.  I think it speaks 
admirably for the human spirit that LowFERs strive to radiate useful signals 
from modest gardens, in the face of continual resistance from landlords, 
neighborhood associations, planning boards, and still higher forms of 
authority such as spouses.

It can't be easy.

73,
John