Topband: Re: Transformer Question

[Ford Peterson]

I am talking about a 4:1 Z (not turns ratio).  The application is a
transmission line model.  I am looking for the equation to transform R+/-j
with accuracy.  From experience, I have found that a 4:1 transmission line
transformer will generally get me into the neighborhood of 4:1 but not
exactly.  The stray reactances do cause difficulty in predictability and in
the real-world some goofy results.  Perhaps there are no assumptions that
can be drawn for modeling other than that the transformer is "perfect."
Lord knows I've got 10 transformers around here in various configurations
and they all result in different transforms when confronted with a complex
impedance.

This whole discussion came up while trying to model transmission lines in
lengths other than 1/4 wl or 1/2 wl, which are straight forward cases.  What
about odd lengths?

Maxwell discusses the issue in Reflections, Terman skirts the issue in
archaic language, and Straw seems to have solved the problem in his program
TLW.  I need to see the equation for incorporating it into a transmission
line model.  When presented with R +/- j at a frequency and a transmission
line of known Zo and length, what is the transform?  Anybody got a clue?
I'm all ears...

Thanks for the help guys.

Ford-N0FP
ford@cmgate.com