It's that time of year when trees and temps become Topband topic. Propagation
must be poor.
Until the supporting tree blew down, my Inv-L for 160 required shortening of
the L in the Fall when the supporting and surrounding trees froze along with
the ground below. However, in mid-winter if the air temp rose above freezing
for a spell (rare in Fairbanks, but…) I'd have to lengthen the same element,
but rarely more than 6". The total length change between summer and winter was
typically about 12-18" for 135' of insulated #12 stranded house wire at 1835
MHz.
The 1/4 WL L paralleled a White Spruce tree for half its length, folded over
the top, but the end was never near another tree for about 20-30'. Winds would
alter the SWR slightly as the horizontal portion changed distance relative to
the 8 tuned elevated radials and ground (dirt) beneath.
Without trees, some of us wouldn't have aerials.
73, Gary NL7Y
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Topband Reflector
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