> It's that thing about "at the top" that probably doesn't get past the
> "garden committee". Folks don't really understand reactionary until
> you've crossed swords with the "garden committee". Maybe something
> that slides INSIDE a fiberglass flag pole.
The major problem with ANY 43 ft vertical is it is nearly like a mobile
antenna on 160. Unless the system has huge losses, RF voltages are off the
map. With low-loss ground systems and loading coils, even the voltage
across a base loading coil is far too high for any reasonable relay.
(I know there have been articles that say otherwise, but I modeled systems
and I actually tested several on 160 meters.)
With a modest ground system, high-Q loading coil, and very good base
insulator, and with only 500 watts applied, arcing distance for connections
across the coil or from base to ground, was nearly one inch through
moderately dry air at sharp points.
If I wanted to run higher power with a 43ft vertical on 160, I'd just add
two or three wires from the top that could fold in and be tied to the
antenna at the bottom. Then, on 160 and 80, they could be fanned out away
from the base and a modest amount of base load used on 160.
Top loading with a "hat" not only gives *up to* four times the radiation
resistance (reducing ground losses), it increases bandwidth and makes base
voltages tolerable.
Or you can just do like the original design plan called for. Have so much
distributed loss voltages never get high.
73 Tom
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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