wrote:
************************************************** **************
Please turn your technical expertise on this example which I
have asked you about many times with no response from you:
http://www.qsl.net/w5dxp/current.htm
At the bottom of the page, the coil is seen to have 0.17 amps
at the bottom and 2.0 amps at the top. With your lumped inductor
way of thinking, how is that possible?
************************************************** ***************
A bench test is fine. An inductor is an inductor.
But the chosen valid model varies depending upon which inductor
it is. Dr. Corum says the model must be changed over at 15 degrees
of the self-resonant frequency. These are velocity inhibited slow-
wave helical coils that we are talking about.
And standing wave current is certainly not traveling wave
current. Remember what Gene Fuller said? Please read it again.
Gene said about standing wave current:
Phase is gone. Kaput. Vanished. Cannot be recovered.
Never to be seen again. The only "phase" remaining is the
cos (kz) term, which is really an amplitude description,
not a phase.
How can one use a signal where the phase is gone to measure phase?
However, inductors were measured in an actual antenna. I measured
current, and Roy Lewallen measured phase and current.
You and Roy measured standing wave current the phase of which is
unchanging over the coil and whip and entire antenna. You should
have realized over the past week that those measurements were
meaningless. EZNEC shows the same thing. Kraus reports the same
thing.
ONE CANNOT USE THE PHASE OF STANDING WAVE CURRENT TO MEASURE THE
PART OF AN ANTENNA THAT A LOADING COIL REPLACES.
... and that for a
reasonable sized inductor the taper is very small.
The present argument is not about taper, it is about how much of
a wavelength a loading coil occupies. One cannot measure that value
using standing wave current as you and Roy did. Roy reported
accurate phase measurements but standing wave current phase is
meaningless since it has unchanging phase.
--
73, Cecil
http://www.qsl.net/w5dxp