[Antennas] LIne Losses

[James Duffer]

>I've been experimenting with a homebrew 2M collinear, and I've noticed that 
>line losses are higher at  lower SWRs than they are at higher readings.
>
>Example,  SWR = 1.0 @ 142 Mc. loss = 15 dB   (yeah I know the elements are 
>too long)
>                SWR = 2.0 @ 148 Mc.  loss = 5.2 dB  Measurenent obtained 
>with an MFJ - 259B analyzer
>
>I've always thout that line losses would be greater with higher SWR 
>readings, not lower. Apparently that's incorrect.  Anyone have any insights 
>as to the reasons for this?

What method and equipment are you using in measuring the transmission line 
losses?  Are those VSWR measurements at the Transmitter end or at the point 
the transmission line connects to the antenna?

Don't become confused with line loss versus VSWR.  The line loss should be 
independent of VSWR. In other words their is a certain amount of 
attentuation caused by the line at a specific frequency and line length, 
with excessive VSWR there is the loss introduced by the line for both the 
forward power and the reflected power.  This is what makes the VSWR look 
better at the transmitter end versus the load end (i.e. the antenna 
connection point).  Hope I haven't confused the issue for you.  But am 
interested in your methods, please post them for the list, I will be 
interested in the comments from other meembers of this list.

73, Jim, wd4air

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