[TowerTalk] Playing with my new VIA Analyst (long)

Robert Chudek k0rc at pclink.com
Fri Nov 11 17:20:12 EST 2005


Yes, I was more interested in repeating the complex impedance values of the 
feed point than the absolute VSWR. Some of the fellows have run my antenna 
through analysis and came up with different values than I was reading using 
the random length of feedline I had dug out of the scrap pile. This was my 
attempt to read the values in the comfort of my shack and not have to climb 
the tower every time I make an adjustment to the inverted vee legs. I just 
hung the new coax a few minutes ago so I will be collecting new data this 

73 de Bob - K0RC

----- Original Message ----- 
From: "Rob Frohne" <frohro at wwc.edu>
To: "Robert Chudek" <k0rc at pclink.com>
Cc: <towertalk at contesting.com>
Sent: Friday, November 11, 2005 1:36 PM
Subject: Re: [TowerTalk] Playing with my new VIA Analyst (long)

> Hi Bob,
> I haven't been back to read the posts that directed you that you need
> 1/2 wavelength of coax to measure the correct VSWR, but it isn't true if
> you have any loss in your coax.  The signal is attenuated as it goes
> down the line and attenuated again as it returns, making the forward
> power you measure OK, but the reflected power is attenuated by a trip
> down the line and back assuming you measure the VSWR at the
> transmitter.
> The thing that does happen at half wavelength intervals along a lossless
> line is that the impedance repeats itself.
> 73,
> Rob, KL7NA

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