I'm finalizing the layout for a tree hung T loaded vertical for TB,
about 85' to the top, two x 45' mostly horizontal loading wires, and
radials elevated 10' above (much?) better than average soil, at least
this time of year when I have standing water among the trees. (Redmond, WA)
I'm taking W8JI's advice and going with the top loaded vertical rather
than a delta loop, particularly after I determined I can squeeze seven
fairly symmetrical 130' radials in (with a cooperative neighbor). I
plan a switched series capacitor feed for bandwidth, with the antenna
resonant at 1815KHz or so.
Now two questions before stringing wire -
1. My new DXE 4 square receive array is outside the radial field, with
the center of the square 82' from the radials perimeter. Does it matter
if the end of one radial is about 30' from a corner 4sq antenna, or
should I pitch the radials to maximize the separation? Even as much as
a 90 degree (or more) segment with no radials? At 90 degree pitch the
nearest radial ends would be about 80' from their nearest 4sq antenna.
2. Now the unusual circumstance - there is a 56' x 70' steel building
entirely inside the radial circle, but at the perimeter. Steel roof,
walls, and Ufer grounded to the perimeter footing. My thinking, not
sure I'm correct, is to NOT attach any radials to the building (12' to
eves, 14' to peak), but nestle it between 2 radials with about 15' feet
of minimum clearance. OTOH, I can connect one or more radials to the
steel, or run one or more insulated radials over the roof to a support
off the perimeter end of the building. And then OTOH, the steel sure
makes this part of the radial field pretty high conductivity. This one
is definitely not in the handbooks or in ON4UN or in the N6LF QEX
articles. btw I have a SteppIR BigIR vertical going on the center of
this roof as a secondary/backup HF antenna.
Inputs appreciated,
Grant KZ1W
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Topband reflector - topband@contesting.com
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