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Old November 30th 04, 07:50 PM
Richard Harrison
 
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Roy, W7EL wrote:
"I`m sure that somewhere in the book the author (Chipman) derives SWR in
terms of reflection coefficient."

I`ve read, here I believe, that Chipman`s book is one of the "Schaum`s
Outline" series. It would need to derive SWR in terms of reflection
coefficient to be complete.

Attenuation of a uniform transmission line is a function of the loss per
unit length and the total length. A line with SWR has higher voltage and
current in spots than a matched line. Thus it has higher loss. Analysis
is complicated in lossy lines due to decline in SWR back from the
reflection point. If SWR at the reflection point is less than 2:1, added
loss due to SWR is hardly detectable. Such a line is considered perfect.

The ARRL Antenna Book has graphs relating SWR to fopward and reflected
power readings as given by a Bird wattmeter. The "Antenna Book" also has
a graph of additional loss due to standing waves versus the SWR at the
load for values between SWR=1.5 and SWR=20.

I don`t have a dog in this fight. There is nothing particularly strange
about solutions to equations which describe particular relations on a
transmission line. The functions are not erratic but continuous and
predictable. Selection of the right formulas is all that`s needed to get
the right answer from the right data.

Best regards, Richard Harrison, KB5WZI