Thread: Dish reflector
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Old April 23rd 09, 06:49 PM posted to rec.radio.amateur.antenna
Art Unwin Art Unwin is offline
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Default Loading coils: was Dish reflector

On Apr 23, 11:26*am, steveeh131047 wrote:
On Apr 23, 4:42*pm, Jim Kelley wrote:



For a more quantitative illustration of how distributed reactance in
transmission lines causes delay seehttp://www.rhombus-ind.com/dlcat/app1_pas.pdf


73, ac6xg


Jim, thanks for the reference.

Perhaps I should have expressed myself more clearly. What I've not
seen, for example, is a lumped-element analysis which takes just the
coil dimensions as input, and predicts theoretically - without a lot
of empirical "tweaking" - the reactance at a particular frequency;
particularly a frequency close to self-resonance. There may be one out
there, but I've not yet found it!

In contrast, the ON4AA calculator - based on Corums' transmission-line
analysis - does just that, and produces results which seem to match
well the EZNEC modelling results.

Regards,
Steve G3TXQ


That is because the transmission line is considered to be within a
arbitrary boundary
where all applicable forces equals zero, ie in equilibrium. Eznec is
also based on the condition of equilibrium as applied by Maxwell in
concert with Newton.
This group is using the conditions accounted on this Earth where as
scientific laws are based upon a Universe within a boundary and not
just the Earth. TRhat is equivalent to saying weight is the same
metric as mass !
Art