I've always been a fan of end-fed half wave wires for portable
operation, as they don't require a ground system, nor do they require a
balun or feedline. The inverted L configuration works well, as the high
current point is a quarter wave from the fed end. Make that as high as
you can. The horizontal part of the wire radiates much like a dipole.
It will also work, perhaps not quite as effectively, simply sloping up
from the feedpoint. Note that this is antenna NOT the same as the usual
quarter wave inverted L, which has maximum current at the feedpoint, and
works more like a vertical.
The downside is that the feedpoint impedance is very high, perhaps 2,000
Ohms, which may be beyond the range of the KX1 tuner. It is, however,
very easy to build an L network to match it. (I can provide L and C
values.) I'd also attach a couple short wires to the radio ground to
act as a counterpoise, though it may not make much difference. A couple
6 foot wires should work for 80 and above.
This kind of antenna will work on any band for which it is a multiple of
a half wavelength, though the radiation pattern will be like a long wire
at higher frequencies. On 10 and 15 meters, if you can get a half
wavelength wire nearly vertical, it will act like a half wave vertical,
which may be better for low radiation angles. I used one of those a few
years ago in the 10 Meter contest from KP2 and, in spite of a terrible
location, a bunch of people heard me.
73,
Scott K9MA
On Mar 15, 2016, at 12:59 PM, Bruce Nourish <w0...@w0mbt.net> wrote:
Hi folks,
For 40m, 30m, and 20m, the KX1 docs recommend a ~24' length of
sorta-vertical #24 wire with shorter counterpoises as a good field antenna.
I've set that up for my KX1 and KX3, and (unsurprisingly) it works well on
both.
For 80m, the KX1 docs recommend a resonant antenna, and I'm considering my
options. Most of what's written out there about low band antennas seems to
be about durable (and heavy) mobile or home installations. Does anyone have
any experience they'd like to share with backpackable lower band antennas?
Options and questions I'm considering include:
* Build a coil big enough to load up my 24' vertical on 80m, with a tap for
60m. Will that be a long enough radiator?
* Figure out the kite-vertical thing, fly a wire close enough to l/4 that
the KX1 can tune it. How bulky would that be?
* Will #24 wire be a decent radiator for the lower bands, or should I eat
the (not-inconsiderable) weight of a bigger gauge?
* Does anyone have any tips on constructing backpackable (minimum weight)
coils? What's the smallest wire and lightest insulator?
* I'm planning a vertical, as this would seem to require strictly less wire
and coils than any dipole or inverted vee, but am I missing some other
offsetting advantage?
Cheers,
Bruce
______________________________________________________________
--
Scott Ellington K9MA
Madison, Wisconsin, USA
k...@sdellington.us
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
