coaxpair reflection coeff angle is 'zero'
Reg,
I am dealing only with the open circuit case and trying to determine the
reflection angle of the reflected signal at the source. In those cases the angle
was always zero.
However the angle calculated is the reflected angle at the termination. In the
open circuit case that is zero.
After making an error here between the effects of odd versus even quarter waves
at the source I am getting closer to being able to measure the impedance of a
loaded vertical 'in the shack'. At the moment this is limited to a single
frequency 'close' to a frequency of interest. But even that is a triumph.
Thanks for the reply. Dan
Reg Edwards wrote:
"dansawyeror" wrote in message
. ..
The program coaxpair does not seem to compute the reflection angle.
Is this an
error? Is the cause known?
Thanks - Dan
=====================================
Dan, I don't know what you mean by "reflection angle".
The program DOES compute the angle of the reflection coefficient. The
answer is in the bottom left-hand corner of the screen.
When the terminating impedance, Rt+jXt, equals line impedance, Ro+jXo,
the magnitude of the reflection coefficient is zero.
But zero magnitude cannot have an angle. Its a mathematical
impossibility.
But when RC = zero the program is obliged to print something for the
angle, so it prints an indeterminate angle which can lie randomly
anywhere between +180 and -180 degrees.
Actually, you can't set the RC exactly to zero because the program
only works to 14 decimal places.
The randomly generated angle can't be used for anything because when
the RC is zero there's nowhere in an equation to insert it. Just
forget about it. It's meaningless.
And even for a very small magnitude of RC the value of the angle
doesn't matter very much. It has little effect on what is being
calculated.
----
Reg.
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