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Re: Vf,Zo,R,G,L,C.....

At 11:08 AM 12/30/98 -0800, you wrote:
snip.........
>Some time ago I posted something about some measurements that I made to
>find these higher-order resonances. They were all there, with the
>expected
>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
>
>

Hi Antonio and All,

I tested my coil WITH the top load in place using a <1 ohm output Z generator:

Fo = 111.6kHz  Very strong.
F(3/2) = 322.6kHz  Pretty good signal.
Then there were two very small 488 and 650 kHz bumps.  Like 4Fo and 6Fo ???

I wonder if the losses get very dramatic at higher frequencies???
Something shure seems to be attenuating the higher harmonics...  All the
transmission line models say there should have been a number of nice higher
frequency harmonics.  Of course, the lumped parameter models say there
should not be...

This may be important if something is really going south at higher
frequencies.  It may explain why lower frequency coils tend to work better.
 If something is getting really lossy at higher frequencies, it would
suggets that coils running in the 500kHz range and above my have
significant problems...

Much to ponder...

	Terry
References: