No, I don't believe 240' is too high - especially if the tower has a base
insulator! It would be so close to 1/2 wave on 160, that it could be fed
very well as a 1/2 wave radiator on 160, either via a parallel tuned tank or
a 1/4 wave of perhaps 450 oh ladder line. A 1/2 wave radiator wis an
excellent transmit antenna, and, because of the high feed-point impedance
can be driven against a very modest ground arrangement
Like you, though, I believe they would do well to put up some terminated
loops, or perhaps a Beverage (or 3?) for receive antennas! A 240' vertical
would, I think, be a VERY noisy receive antenna. If they put up a KAZ
terminated loop that only requires one overhead support, they could steer it
around with ropes and weights on the ground. The KAZ is like ON4UN's FO0AAA
160 receive loop.
73,
Charlie, K4OTV
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Richard
Karlquist
Sent: Tuesday, February 25, 2014 3:38 PM
To: topband@contesting.com
Subject: Re: Topband: AM broadcast tower and 160m dxpedition
Congratulations on your adventure.
In the past, I have seen some of these AM tower efforts
ruined by lousy receive conditions. I suggest you
get an advance team out to the site to check
out the noise level etc. and maybe put up some
temporary beverages, loops, whatever and LISTEN
on them. Use WWV and WWVH on 2.5 MHz as a beacon.
Others can comment on whether 240 feet is too high.
Rick N6RK
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