Topband: AM broadcast tower and 160m dxpedition

[Charlie Cunningham]

That's not so surprising Gary !!  te Way the Beverages and similar slow-wave
antennas work is that they depend on the lossy GND  underneath for their
operation, so a salt marsh would not be a very beneficial GND structure
under a Beverage!

73,
Charlie, K4OTV

-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Gary
Smith
Sent: Tuesday, February 25, 2014 5:09 PM
To: Topband at contesting.com
Subject: Re: Topband: AM broadcast tower and 160m dxpedition

My Inv-L is on a salt marsh on Long Island Sound in Connecticut & I 
ran two bidirectional 860' beverages over the salt marsh. I had 
terrible results with the beverages, very noisy and hardly any 
improvement over the Inv-L, much of the time the Inv-L was more 
effective on Rx. With that, my experience of beverages & salt marshes 
says to avoid this route. 

I ended up with a HI-Z Triangular array for Rx and it works very well 
at the same location.

Gary
KA1J

> 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 at contesting.com] On Behalf Of Richard
> Karlquist
> Sent: Tuesday, February 25, 2014 3:38 PM
> To: topband at 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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