Hello Merlin,
Your idea will work Fine Business as others have already mentioned, and yes
it is a great project to get into building, as there's very little to go
wrong. This method is frequently done with the ever popular Lakeview
Hamstick antennas and clones.
A friend of mine demonstrated one of these to me this past summer using 2
40m mobile Hamstick clones, oriented horizontally, over ground near salty
water, and up only 10 ft. This antenna is only 16ft long, compared to a
full-size 40m dipole at 66 ft. I was skeptical! Damned if signal reports
from the same station weren't within 1 S unit or less compared to an 80
delta loop up 20 ft at the same location!
He used a coaxial choke balun at the feedpoint and rotated the dipole to aim
at the station we were working. It's a little trickier tuning loaded
antennas as a dipole. First you must tune by adjusting only 1 antenna at a
time for the best resonance and best SWR. Once they are matched, then you
tune both Hamsticks together by adjusting the whips equal amounts on BOTH
sides to center the resonance on your desired frequency.
See Lakeview's dipole adapter at: http://www.hamstick.com/901.htm
Also, a more developed version and parts at: http://www.buddipole.com
The only rub is brewing your own mechanical arrangement, if you prefer to
build it all, to be strong enough, depending on your intended use.
See this article at LB Cebik's excellent site:
http://www.cebik.com/wire/1712.html
This shows some mechanical construction ideas to help get you started.
The stainless whips will be expensive, unless you already have them.
Galvanized EMT conduit will work quite well, is cheap, and available just
down the road at the home store. Being larger in diameter than the whips,
the resulting antenna will have a bit more bandwidth. The larger the dia,
the more of the 10m you can cover with good resonance.
The whips will probably stand up better to ice and wind, if you plan to
mount the antenna on a tower. Some droop won't matter at all.
Stainless whips are hard to trim. One trick is to file a notch using a
triangular file, then snap the whip apart. Then you must file or grind the
end back to a rounded shape. If you cut them too short, don't worry. You can
attach a 6" wire tuning stub to each end using a ground lug connector, and
trim the wire to resonate the antenna.
Happy building!
--...MARK_N1LO...--
Merlin asks:
<<is there any reason why you could not use 2- 102" CB whip antennas for a
10M dipole?
Connect the shield of the coax to one and the center of the coax to the
other one using a homemade bracket out of something non conductive to bolt
the 2 whip antennas to,at 180 degrees from each other...like this <---------
----------> ...snip>>
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Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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