At 09:17 AM 6/7/03 -0500, tad danley wrote:
>Tree wrote:
>
> > If your radio does six meters, a 5/8 wave 2 meter mag mount works
> > FB as a six meter antenna.
> >
> > Tree N6TR
>
>Has anyone tried to push the envelope and use a 5/8 wave antenna mobile on
>432 MHz as well? It will be the wrong polarity, but I'll give it a
>try. Just got the FT-100D installed in the Jeep and won't have the time
>to put anything better in place before the VHF/UHF contest.
I doubt that the feedline will match at all. A 5/8 wave antenna has to
have a coil to match it, and I'll bet the coil will simply act like a choke
at 432. If the match is bad, it drives the feedline loss (already pretty
substantial at 432 MHz for RG-58) through the roof. I think you'll be
pushing your luck to work anybody unless you're in a pretty outstanding
location.
Right after buying our IC-706MKIIG's in 1999, K9TM and I decided to try our
first pseudo-serious rover effort in the June contest from here in
MI/OH. We stuck a 706 in my Jeep Grand Cherokee, and put together a 15'
rotating portable mast in a "Big Foot" mount (see AES catalog) held up with
a bracket off the luggage rack. On this mast we mounted a Cushcraft 3L 6M
and 5L144/5L432 yagis and an armstrong rotator. At the last minute, we put
a 2M 5/8 wave mag mount on the roof to operate on 2M and 6M while mobiling
between fixed locations where we put up the big antenna.
This was just a "Saturday afternoon" type effort from three grids. No high
hills, just rovering around the flat land out here in the midwest. We had
lots of fun and worked stations on all three bands (50/144/432). However,
we did not work, nor hear, a single station with the 5/8 wave mag mount on
either 6M or 2M.
YMMV - just a caveat to not expect miracles with such a simple antenna. I
would think that a short dowel rod mast fastened to a magnetic base, and
holding up 50 and 144 (also usable on 432) inverted vees (acting as guy
lines) would work a lot better. True, you gotta build something, but
that's what makes it fun.
K8CC
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