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Re: [TowerTalk] Measuring coax loss

To: <>, "Pete Smith" <>
Subject: Re: [TowerTalk] Measuring coax loss
From: "Tom Rauch" <>
Reply-to: Tom Rauch <>
Date: Sun, 26 Dec 2004 12:19:19 -0500
List-post: <>
> I presume that the mixed impedance of this line is such
that the built-in
> loss calculation provided by the 259B is not reliable.  I
also wonder about
> the accuracy of the equation from the RF-1 manual in this
case-- can anyone
> refresh my memory on it?  Is it really necessary to
measure only the 75-ohm
> portion of the line with the 259B, then the 50-ohm
portion, and add the
> power ratios in order to compute the total loss?
Alternatively, is there
> any way I can  do it with the line in situ?  Sorry, but my
theory just
> isn't strong enough to answer the question for myself.

The MFJ manual warns users loss measurements are only
accurate when the line Z0 matches the analyzer design
impedance, or 50 ohms.

What is the formula for the Autek, or can you describe what
you are measuring? If I knew what they want you to measure,
I can tell you if it will work.


See:  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

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