Cecil Moore wrote:
Jim Lux wrote:

I doubt there's anything special about the 22 ft.


I've been told that 22 ft. is special, i.e.
virtually everyone can get his vertical
section 22 feet off the ground. (The original
Windom had a vertical radiating section.)

As opposed to 20 ft or 21 ft or 25 ft?

I find it hard to believe that there's an electrical reason for 22ft.
Mechanical or convenience I can believe.

Maybe it fits well with the length of their isolators, etc. and matches
a convenient pole height (e.g. isolator plus sag plus 22ft plus whatever
exactly matches 26 ft 3" or whatever the pole is)

On Tue, 21 Aug 2007 17:34:23 -0700, Jim Lux
wrote:

Cecil Moore wrote:
Jim Lux wrote:

I doubt there's anything special about the 22 ft.


I've been told that 22 ft. is special, i.e.
virtually everyone can get his vertical
section 22 feet off the ground. (The original
Windom had a vertical radiating section.)

As opposed to 20 ft or 21 ft or 25 ft?

I find it hard to believe that there's an electrical reason for 22ft.
Mechanical or convenience I can believe.

Maybe it fits well with the length of their isolators, etc. and matches
a convenient pole height (e.g. isolator plus sag plus 22ft plus whatever
exactly matches 26 ft 3" or whatever the pole is)

Looking through the Radio Works catalog, the vertical radiators are
22' for 80m & 160m versions, 10' for a 40m version, 18' for an
enhanced 40m version of the Carolina Windom.

So they're figuring something, what, not sure of...

bob
k5qwg

On Wed, 22 Aug 2007 11:13:11 -0500, Bob Miller wrote:


Looking through the Radio Works catalog, the vertical radiators are 22'
for 80m & 160m versions, 10' for a 40m version, 18' for an enhanced 40m
version of the Carolina Windom.

So they're figuring something, what, not sure of...

bob
k5qwg

My guess is that the length of the vertical segment is such that it acts
as a matching segment to keep the overall impedance of the antenna at a
reasonably matchable level.

That was my primary reason for choosing the New Carolina Windom, over the
venerable G5RV. The impedance mismatch onthe NCW is almost never over
3:1. Which is all that my auto-tuner is rated to handle, while the G5RV
can easily exceeded 5:1 on some bands. (I saw an article that did a
great job of comapring impedances between these two antennas, but I can
not seem to find it now)

I built my own NCW based on the measurements in this QRP Expressions
article. http://www.w5fc.org/files/QRP%20Expressions.pdf

I liked it so much, I built the larger 80m version, with measurments from
the RadioWorks website. I did not have a 22' of coax handy at the time,
so I used a 14' piece that was left over from another project.

It seems to work just fine on everything but 17m. The autotuner tried
and tried but could not cope. Finally I replaced it with the correct 22'
lenth, and 17m once again tunable. So there is -something- to it.

--Teh