My top loaded "T" top band vertical is up. 85' vertical, 43' each side
"T" and 3 elevated 123' radials at 10 to 12'. Resonance Z is currently
36 ohms and 90KHz 2:1 swr BW. EZNEC+ shows a resonance Z of 25 ohms
with 4 elevated radials, so I presume the delta is ground loss. The
antenna is tree supported in a 40% grass/60% forest (hemlock. cedar,
fir) area with a very wet, some standing water ground surface. Buried
radials are not feasible.
I can/will add 4 more elevated 123' radials for 7 total, but am debating
what to do about a 4000 sq ft all steel 13' tall nearly flat roof
building within 1 quadrant of the radial field, about 60' from the
antenna base. "Don't ground elevated radials" makes sense to keep
antenna return currents out of the earth. However, when a large area of
"perfect" grounded conductor is available, why not connect to it? (the
building has steel side walls and a Ufer perimeter footing ground).
Then a secondary question is "how many elevated wires to connect to the
building?" Three makes sense to me, given the angular spacing of the wires.
Can any modeling software handle such a configuration?
Whatever is up gets a try out on the CQ 160m SSB this weekend.
Grant KZ1W
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Topband Reflector
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