Re: Topband: 160 vert puzzle

[Shoppa, Tim]

Is this all being done with the portable antenna analyzers? Those can be 
surprisingly susceptible to nearby BCB stations that are out of ham bands, but 
detected by the analyzer and influencing the measured numbers/curves.

These little analyzers are completely useless at my QTH (100V Pk-Pk levels at 
high impedance points. I can light a neon light bulb on modulation peaks of 
the local 630 kHz BCB station.)

With it being influenced by hand capacitance at the bottom I would wonder if it 
was FM band BCB pickup. At my location it's AM band BCB pickup and I would be 
surprised if hand capacitance could do that. On my bench scope, I can see the 
FM stations quite clearly changing level depending on hand capacitance.

Tim N3QE

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Topband Reflector

Re: Topband: 160 vert puzzle

[jcjacobsen]

How do to all. 
Glenn is chasing a 160 meter antenna puzzle, where the SWR on a vertical 
supported by a 4x4 increases when he touches the top of the 4x4. 

First off, the disclaimer: I AM NOT AN ANTENNA GURU! 

With that said, Glenn, does the same thing happen when you bring your 
finger/hand CLOSE to the 4x4 with out touching it??? I think what is happening 
is your hand is coupling capacitively to the antenna. Moving your hand up and 
down is changing where it is coupled to the vertical and because of a different 
level of voltage and current, the SWR will change. I noticed that also on my 
temp low band/winter vertical that is insulated from and supported by a tripod. 
Touch the tripod and the SWR goes up. Come close to the tripod, same thing. I'd 
say, don't worry about it. Just use it. 

73 es GDDX 
K9WN Jake 



Date: Mon, 7 Jan 2013 21:30:33 -0500 
From: Glenn Biggerstaff  ww4...@gmail.com  
To: topband@contesting.com 
Subject: Topband: A 160 Meter antenne puzzle 
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Topband Reflector