HENRYPOL@aol.com wrote:
>
> Chuck,
>
> Ditto to K7LXC's response. Please do go on and on! I would be interested in
> any comments you may have about quads and other wire antennas for 10 meters.
Hi Henry,
I have not had much success with wire antennas for 10, although I have heard
of good success with Vee and Rhombic antennas. Quads are a different story.
I have a 30 foot boom tri-band quad which is not up right now. It has 4
elements on 20 and 15 and I interlace elements for 7 elements on 10. It will
be going up at 75 feet here soon. (I am at a new QTH.)
I sure wish I had it on Sunday of the 10 meter contest. The rain static at
K5XI on the high yagi was close to S-9 at times. The static would have been
much lower on the quad. It also performs well during high K indices,
however, that may be a function of the height.
I originally had it at 130 feet and I did not feel it performed as it should.
I moved it to 75 feet and it was gangbusters! In one contest with a lot of
high K indices, I made 98% of my Qs on it. I have no explanation for this.
Bad coax? Angle of radiation? (It was over salt water at that QTH.)
A great property of a quad is that you can have a tri-band quad that performs
as well as three mono-banders. Makes a great low antenna.
I also have a 16 foot boom that I have used as a 4 el 10 meter quad to fix on
South America at 40 feet. In the slow contest afternoons South Americans
will often say I am the loudest signal on 10 when I am using it. Ten meter
spreaders are short and this can be a cheap and easy weekend project.
Home Depot type places have aluminum angle which you can cut and attach to
the boom with muffler clamps, pinning it together in one place. Spreaders
can be hose clamped to the angle. Feed it with a balun. It will be a 50 ohm
feed without any matching. (As are all 3 or more element quads with proper
spacing.) My kind of easy project!
By the way, I always use the "diamond" configuration on quads. That is with
the corners of the elements pointed up & down and fed at the bottom corner of
the driven element with a large air core balun. You can usually reach the
feed point from the tower. This is the weakest point because of the weight
and wind resistance of the balun. You may want to reinforce the spreader
here with some aluminum from an old crashed beam element. (I never use
aluminum spreaders.)
73,
Chuck, KE5FI
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