From: "Mike Dennison" <mike.dennison@rsgb.org.uk>
To: rsgb_lf_group@blacksheep.org
Date: Wed, 6 Jun 2001 12:21:22 +0100
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Subject: Re: LF: Wire in the Air etc
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>        About antenna .  I wonder if the increase in efficiancy is caused
> by the higher antenna capacity which permits smaller coil and therefore
> less loss due to coil resistance.  This might also explain the big
> signals from  Jack and the OH station.  I am thinking of putting up a 50
> ft vertical with a 400 ft long wire from top.   How does that sound?
>       John VE1ZJ

You will only save an ohm or two on the loading coil, whereas there is much 
more to be saved in the earth resistance. As with most amateur radio, the big 
signals have lots of wire at a good height. 

Your projected antenna would be the envy of most Eu operators, but if you 
can get it higher - even at the expense of length - it will work better. ERP is a 
function of effective height squared. The effective height is directly 
proportional to actual height, but the relationship between actual and real 
height is not affected much once you have a good size top section, so actual 
height is the most important. Of course, as Laurie has demonstrated, it also 
helps if you can increase the current significantly with a bigger top section, as 
ERP is also a function of current squared.

Mike, G3XDV (IO91VT)
http://www.lf.thersgb.net