Barry, When I used to run a 4 element lazy vee antenna (similar to your sloper
array) I put two insulators at the proper position at the bottom end of each
dipole element. I was able to tune the array so that both insulators were
jumpered for 3525 kHz, one insulator was jumpered for 3625 and no insulators
were jumpered for 3795 kHz. I simply used electricians wire nuts to jumper
across the insulators by twisting two wire pigtails together. I had to do the
jumpering from a tractor front-end loader about 12 feet off the ground, but it
was quick and easy.
73/Mike, N7ML
Barry Kutner wrote:
> I use 3 "vertical slopers" around the tower. I believe it was
> originally written up by K8UR, and is in the ARRL Antenna Handbook
> (mine's about 10 years old, don't know if it's still there) as a 40m
> antenna, using 5 slopers.
> Start at the top of the tower with one end, then the lower end is
> pulled back in to the tower, so the center insulator is half way up,
> and pulled out by a rope and staked to the ground. It looks like a
> diamond configuration. Pulling the lower end back in cancels out the
> horiz component and lowers the andle of radiation. The wire is fed
> with a 3/8 wave of coax (I used RG8X) to a relay switch box. This
> length of coax is supposed to act like a stub, making the non-selcted
> wires act like reflectors.
> To switch from 80 to 75, I go outside and fold back about 10 ft at the
> bottom. In the near future, I plan on adding some relays to do this
> from in the shack, and if anyone has any suggestions on physical
> construction details (what to use to keep water out, how to support
> it, will the control wires bring RF into the shack, etc.), I'd apprec.
> it.
> I'm very pleased with performance, and at times see up to 20 db, F/B or
> F/S depending on the path.
> 73 Barry
> --
> Barry Kutner, W2UP Internet: w2up@mindspring.com
> Newtown, PA Frankford Radio Club
>
>
>
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