Robert Conley <
[hidden email]> wrote :
> Since I suffered
> an attack of
> senility when I ordered my K1-2 (I ordered it with 80m and 40m) and a
> KAT1. I wish to
> utilize a random length wire for it Should it be double the KXAT1's
> recommendations
> (48-56') with a ground system of 1/8 wavelength on the lowest band
(32'
> on 80m)
> double that of 40/30/20m.
Rob, as someone else suggested the trick is to provide an impedance in
the
range that the tuner can match and the best bet is to find a wire
length that is not
near a multiple of a half wavelength on any of the bands that you wish
to
operate, as half wave multiples will result in a very high impedance.
The good news is that someone has already done this. A UK ham named
Alan Chester
G3CCB (sk) wrote an article titled "Taming the End-fed Wire" that has
appeared in
a number of RSGB publications and is in a book being sold by ARRL called
"The Antenna File".
In this article Alan has mapped out wire lengths versus bands and
provides a chart
which quickly allows one to figure out what bands are a "no go" with
different wire
lengths. Alan recommends three wire lengths. 10 meters, 15 meters and
26.5 meters.
Any of these lengths should theoretically be ok for 80M and 40M.
Please note that the 10m wire length doesn't work on 20M and 10M, the
15m wire length is a no go on 17m, 15M and 30M and the 26.5 meter wire
probably won't match on 10M.
I would suggest trying the 15m wire, which works out to about 49 feet.
I have had good luck with my KX1 and the suggested 28 ft vertical wire
using 5 X 16ft ground radials made from a piece of computer ribbon
cable.
on 40M, 30M and 20M. I leave the first 2 or 3 feet intact and split out
the
individual conductors on the remaining length. This is pretty easy to
deploy.
I would suggest that you stick with the 1/8 wave on the lowest operating
frequency and deploy as many radials as you find practical (up to about
2 dozen, as it is a case of diminishing returns for this length of
radial beyond
that number).
Your mileage may vary as it is all dependent on the matching abilities
of the
KAT1.
Michael VE3WMB
P.S. Let us know how you make out.
_______________________________________________
Elecraft mailing list
Post to:
[hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
http://mailman.qth.net/mailman/listinfo/elecraft
Help:
http://mailman.qth.net/subscribers.htmElecraft web page:
http://www.elecraft.com
Locked
