I could be wrong, but here's what I was getting at. You should be able
to vary the feedpoint impedance, where ever the feedpoint happens to be
(in this case, the end), by varying the distance between the attachment
points of the two conductors of the feedline. The closer they are
together, naturally, the lower the impedance. It should be possible to
find a match in this way. Part B would be to keep the feedline from
trying to radiate.

ac6xg

John Smith wrote:

Jim:

Well, I have found terminology interesting. And, depends on whose you
use, there is ARRL of course, then there are a bunch of in-house tech
docs from industry.

Take what I have been accustomed to calling a 1/2 wave monopole--for
example: on 10 meters, it is about a 16 foot metal length and end fed.
An EFHWA. Most frequently fed through an L-Match or 1/4 wave matching
section--sometimes uniquely though an unun.

However, if you attempt to feed it in the middle, it suddenly becomes a
dipole, the equiv of two 8 ft-1/4 wave monopoles connected at there
bases, and would take a unique feed I am not familiar with, as each 1/4
wave section would need be fed out of phase--and this would be difficult
with the impedance so close to the feedline (coax in this case) and
having the 1/4 monopoles connected (notice, I didn't say impossible!
grin.)

Spilt the 1/2 monopole and center feed it and it becomes two 1/4 wave
monopoles (commonly referred to as a 1/2 wave dipole) and can be center
fed with convention means quite easily, as a dipole (indeed, many feed
them directly from coax--the more picky through a isolation balun or 1/4
wave section.)

However, two 1/2 monopoles, connected at their bases (actually a 1 wave
length single element) begins to accept center feeding with quite
conventional means (ant feed point is high impedance), although in ARRL
literature this would be referred to as 1 wave dipole, still it could be
modeled as two 1/2 wave monopoles being fed out of phase.

All I am concentrating on is the EFHWA (and, if setup right requires no
counterpoise), and various means of feeding it, modifications and
experiments...

Warmest regards,
John
"Jim Kelley" wrote in message
...


John Smith wrote:


might just work, if the total element length is 1 wave! and in a
dipole configuration...

You're thinking too far outside the box. Reel it back in a smidge.
:-)

ac6xg