My program assumes line Zo is purely resistive. But at HF it is
practically impossible to tell the difference in line loss between an
angle of 0 degrees and 1 degree which is the range of Zo angles
involved.

I have the exact formula for any line but its far too complicated to
write here.

I didn't use it in my program as it would have meant another input
value for no useful purpose.
----
Reg

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"Owen" wrote in message
...
On Wed, 6 Jul 2005 23:48:53 +0000 (UTC), "Reg Edwards"
wrote:

Owen,

Your formula is too short to be anything but an approximation. It
may
be a very good approximation. On the other hand it may contain
exactly the same errors as whatever you may have checked it
against.

The exact formula is exceedingly involved and occupies about half a
dozen lines of source code in new program SWRARGUE which by
coincidence I have just placed in my website.

I have calculated the loss using P=Real(V*I*) at the two points, and
it is long winded. Michaels approach produces the same result, and
the
coding is more elegant, probably faster to calculate. He is a SK, so
I
can't ask him, but in the hope that it is well known, someone might
know of the derivation.


You can check your formula against my program. Let us know how you
get
on.

Your calculator does not allow complex Zo does it? Doesn't that mean
it assumes a distortionless line. I am calculating loss in the
general
case.

Thanks...

Owen

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