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Old February 29th 08, 06:35 AM posted to rec.radio.amateur.antenna
Ed_G Ed_G is offline
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First recorded activity by RadioBanter: Dec 2007
Posts: 69
Default SGC coupler to Dipole feedling question



Your antenna is already quite compromised with a
~490:1 SWR on 75m at the antenna feedpoint. The line
loss with RG-213 is about 4.5 dB and the tuner is
required to match 0.55-j48 ohms, another lossy
situation. Your antenna system efficiency may be ~10%.

How about turning your 13 foot pole into a radiator
and using the dipole wires for a top hat?



The aluminum 2" mast will be side mounted on the wood building...
about 5 feet below the edge of the roof. The remaining 14 or so feet
will be above the roof. With two 35 foot wires off the top, do you
really think that would work to our needs better? There is one
problem with this setup, though.... I do not think there is a suitable
ground on the building roof. I suppose it is possible to run a simple
wire straight down from the area near the bottom of the mast to the
ground..... the SGC-237 would still have to sit on the roof and be
connected to this now lowered feedpoint.....

I think it would be easier to extend the length of our inverted V
legs. I had posted their length between 35 and 40 feet, but if we run
out of building to extend the ends to, I suppose we could go on
straight down from the end mounts, toward the ground a bit. Even an
additional 10 feet could be had on each leg with the new ends being
still 10 feet above the ground. It IS a wooden structure, for the most
part.

Ed