Tesla List wrote:
> A single lossy line model. The corums like the balanced pair but that does
> not seem realistic to me... But perhaps they have a good reason to use the
> two lines that I don't understand...??
The model is always the same for a TEM line. Only the parameters change.
> BTW - the lumped models give pretty much the same waveforms and results
> just like I always said :-)) However, with the transmision lines you can
> see the impulse effects of the coil's 3/2, 5/2, 7/2... wavelengths
> reflecting back which is sorta neat... but for most uses, the lumped
> parameters ar vastly easier to deal with and give perfectly good results.
Some time ago I posted something about some measurements that I made to
find these higher-order resonances. They were all there, with the
voltage distributions along the length of a coil, but all at the -wrong-
frequencies (significantly lower than what the TEM line predicts).
I attributed the difference to the fact that a vertical coil is not a
TEM line, because there is significant magnetic field in the
vertical direction. A model of this behavior can be obtained by
including coupling between successive LRC sections of the usual TEM
model, but I didn't try to derive one.
Antonio Carlos M. de Queiroz