"dansawyeror" wrote in message
...
Thanks,

Can you explain "transmission performance". Is it as measured and
the source,
Zin? What is the range of Reflection Coeff? Is it a percentage? Is
refl. coeff.
angle measured at Input?

===================================
"Transmission performance" is just a descriptive term relating to how
well a line works compared with what is expected from it. It is not
measurable. It is a way of referring to the very many different
characteristics / properties / attributes of anything which performs.
It can be good, poor, better, worse, etc., etc.

The "reflection coefficient" is a dimension-less ratio, the
mathematical relationship between line Zo and the line terminating
impedance Zt.

RC = ( Zt - Zo ) / ( Zt + Zo ).

In general, both Zt and Zo are complex quantities and therefore RC
possesses both magnitude and a phase angle.

The magnitude can be anywhere between 0 and 1+Sqrt(2) although only in
very exceptional circumstances will it exceed 1.0 It is never
expressed as a percentage.

The phase angle can lie in any of the 4 quadrants of a circle. i.e.,
it can have an angle anywhere between 0 and 360 degrees. When
performing calculations it is more comvenient to refer to the angle as
lying between -180 and +180 degrees.

It can be referred to any point along a line. The angle, as in a
vector, rotates as the reference point moves away from the termination
towards the generator.

As you are probably aware, RC is closely related to SWR. SWR can be
calculated from RC. But RC cannot be calculated from SWR. This is
because RC conveys twice the amount of information as SWR. When
calculating SWR from RC half the information is lost. The angle of
SWR disappears.

SWR is the end of the line! Whether SWR is measured or calculated you
can't go much further.

But SWR / RC is a fascinating subject.
----
Reg, G4FGQ.