View Single Post
  #40   Report Post  
Old March 23rd 09, 06:25 PM posted to rec.radio.amateur.antenna
Tom Donaly Tom Donaly is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 274
Default colinear representation in NEC

Jim Lux wrote:
Owen Duffy wrote:
"Tom Donaly" wrote in
:
...
Why would NEC reduce a TL two-port to a lumped load? Two-port
parameters can handle transmission line problems quite well without
the simplifying assumption that all components are of zero length.


Hi Tom,

I expect that NEC does model the propagation delay from end to end on
a transmission line. My comment was that NEC reduces a s/c TL stub to
a lumped load for the stub input end which is inserted in the vertical.


No it doesn't do prop delay. It does a steady state model. The TL is
just another two port that gets dumped into a giant matrix which is
solved as a system of linear equations. Think of TL as a special case of
NT.


What kind of two port does NEC use, Jim? What is "just another two port?"
73,
Tom Donaly, KA6RUH