View Single Post
  #640   Report Post  
Old March 23rd 06, 06:01 PM posted to rec.radio.amateur.antenna
John Popelish
 
Posts: n/a
Default Current through coils

Cecil Moore wrote:
John Popelish wrote:

Oh poo. At current nodes charge piles up and spreads out, on
alternating half cycles. For one half cycle, the pile is positive,
and for the next it is negative. This is a basic transmission line
concept. If transmission lines had no shunt capacitance, there would
be no place to put this charge. But there is, so it is no problem.
Whether the transmission line is coax, twin line or a slow wave helix
makes little difference. The process is similar. Isn't this what you
have been arguing?



If the forward traveling wave is equal in magnitude at both ends of the
coil, there is no net storage of energy due to the forward traveling wave.


Over a complete cycle, I agree, Within a single cycle, standing waves
slosh charge back and forth between adjacent current nodes, piling up
positive charge at one and negative charge at the next. This is the
reason that the voltage peaks at the tip of a quarter wave antenna.
It is a current node (because current has no place to go from there),
so charge piles up and produces voltage. But over a complete cycle,
the net charge movement is zero (the positive piles are he same size
as the negative piles).

If the reflected traveling wave is equal in magnitude at both ends of the
coil, there is no net storage of energy due to the reflected traveling
wave.


Same thing I said last paragraph.

Superposing those two waves still results in no net storage of energy.
Sorry, got to hit the road.


I'll put this on hold till you get back. Have fun.