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Topband: K9AY Center support

To: <topband@contesting.com>
Subject: Topband: K9AY Center support
From: W8JI@contesting.com (Tom Rauch)
Date: Fri, 22 Nov 2002 07:59:04 -0500
> I keep reading about this, but have not seen any practical "how to"
> information that is detailed enough for me to understand.  Is the
> objective of detuning simply to move the resonance out of the 160M
> band?  If so, how far out is "enough?"

What you generally want to do is cause an equal and out-of-phase 
current in the drop wire that opposes radiation from the tower.
 
The only accurate way to do that is with an actual signal strength 
test.

The second method is to adjust for maximum current in the detuning 
wire, but this only works when the tower is less than 3/8th wl or so 
long electrically. If the tower or structure is electrically longer 
than that, you have to use a FS meter and check patterns.

Of course you could use a portable signal source, instead of a FS 
meter, and use a receiver on the RX antenna instead of a small 
transmitter. Reciprocity works.73, Tom W8JI
W8JI@contesting.com 


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