Topband: EZnec - 4nec2 - MODELING THE 1/4 SLOPERS.
jim at audiosystemsgroup.com
Sat Mar 8 13:38:16 EST 2014
On 3/8/2014 9:08 AM, Herb Schoenbohm wrote:
> IMHO a wire 1/4 wave length long wire should preferably be
> electrically connected to the tower and fed from the bottom of the
> slope against a good ground system.
That depends on the height of the tower. I have two sloping wires on
opposite sides of my 110 ft tower (with SteppIR and 2M long Yagi on top)
that are INSULATED from the tower and each fed from the bottom against
four radials elevated about 20 ft. The tower is grounded and has a dozen
or so quarter wave radials. The wires are held 5 ft away from the tower
at the top by a 10 ft section of 4-in PVC conduit. One faces to 70
degrees, the other to 270 degrees. NEC predicts the same gain of 2-3 dB
with F/B of about 6 dB, and that's about the way they hear. I feed one
or the other, with a stub in the shack that opens the feed of the
antenna not being driven.
73, Jim K9YC
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