View Single Post
  #19   Report Post  
Old May 8th 07, 05:16 AM posted to rec.radio.amateur.antenna
Gene Fuller Gene Fuller is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 342
Default Phase Shift through a 75m Texas Bugcatcher Coil

Richard Harrison wrote:
Cecil, W5DXP wrote:
"No, just that phasing of RF signals is what is confusing the DC gurus,
just like AC phasing confused Edison."

In W8JI`s pages I found this on the subject of "Mobile antennas, short
verticals, loading" :
It`s long and Tom warns about taking anything from context, so it should
be searched out and read in its entirety. I have no quarrel with most of
Tom`s pages but find this statement curious:
"When current flows in the transmitter-end of the coil, a magnetic field
is created. The time-varying magnetic field causes charges in the other
turns to instantly move."

Instant movement of charges is instant current, and everyone knows that
current in a coil lags the voltage.

Best regards, Richard Harrison, KB5WZI


Richard,

This is one of those situations where the exact definitions are
critical. In the case of "current lags voltage" the current is measured
through the coil and the voltage is measured between the ends of the coil.

The voltage at the input of the coil (to some reference point) is not
important; only the voltage across the coil matters. Since there is
nothing in the problem statement about the coil output voltage it is not
possible to determine if there is any violation of "current lags
voltage" or not.

I am not saying anything about the assertion from W8JI. The "current
lags voltage" principle simply does not settle anything in this case.

73,
Gene
W4SZ