Yuri Blanarovich wrote:
Any experiences out there, rather than more "reasons" why it ain't so?
Proper accommodation in modeling programs can give substantial improvement in
loaded elements modeling.

Assume a transmission line with an SWR of 10:1. Put a series inductor
in series with the transmission line. Assuming negligible losses, the
forward current is the same at each end of the coil and the reflected
current is the same at each end of the coil. The question is: Do the
superposed currents, Ifwd+Iref, remain constant? Of course not, because
of phase shifts. With a large enough coil, one could cause a current
maximum point on one side of the coil and a current minimum point on
the other side.

That same principle holds true for standing wave antennas which are
antennas with (surprise!) standing waves. The current is NOT the same
at each end of the coil (unless a current maximum or current minimum
occurs in the middle of the coil). However, for traveling wave antennas,
the current at each end of a loading coil would be close to equal.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Thanks Cecil,
the standing waves do it again!

So far the best argument against W8JI's Kirchoffs and Ohms!

With your permission I will post this public posting back at the eHam.net.

Now see what Reg says, hopefuly after reading the article.

Yuri

Yuri Blanarovich wrote:

Thanks Cecil,
the standing waves do it again!

See if you can get Tom to assert that the current into and
out of a coil in series with a transmission line with reflections
is also constant. :-) Same principles apply.

So far the best argument against W8JI's Kirchoffs and Ohms!

You can get a ballpark estimate of those currents by comparing
a 1/2WL dipole to a loading coil dipole. Assuming the following
two dipoles are resonant on the same frequency:

-----y----------x-----FP-----x----------y-----

-----coil-----FP-----coil-----

Assume the feedpoint impedances are the same and the losses in
the coils are negligible. The net current into the coil is close
to the current at 'x'. The net current out of the coil is close
to the current at 'y'.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Can any of you guys tell me which of the waves on the antenna does the
radiating - is it the forward or is it the backward wave ?
---
Reg

Reg Edwards wrote:
Can any of you guys tell me which of the waves on the antenna does the
radiating - is it the forward or is it the backward wave ?

An electron experiences the sum of those two waves and emits a
photon when it is energized enough. So the answer is both.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Reg Edwards wrote:
"Can any of you guys tell me which of the waves on the antenna does the
radiating - is it the forward or is it the backward wave?"

I agree with Cecil, "So the answer is both."

Think of a traveling wave antenna, the rhombic. When it is properly
terminated, there is no backward wave and the radiation pattern is
unidirectional. Eliminate the termination resistance and a total
reflection occurs at the antenna`s far end. Now the rhombic is a
bidirectional antenna.

Best regards, Richard Harrison, KB5WZI