My previous request for suggestions for a relatively
simple/transportable TB ant got some responses that have been
incorporated into a design and construction that might be useful to
others. It is a dual band 160/80 trapped vertical/T with two load top
wires and two elevated gull wing radials using the spiderbeam 60' mast.
It is relatively compact and works respectably on 160 and perhaps
somewhat better on 80.
Highlights are only 55' of the mast is useful (bending), radials are 75'
(tuned to 80) and ~ 17' high, the 2 top load wires are 60' (tuned to
160), trap is coax type (Low-Z wired), a single "hairpin" match shunt
coil setting allows no-tuner 160/80 use without any switching with
limited BW and use on 160 requires a GOOD common-mode choke (this is a
rather OCF antenna on 160).
The hairpin matching requires patient trimming of wire lengths so if you
are willing to complicate things a bit, a capacitor could be tossed in
for an L-match. It is also very likely that putting this antenna up at
another location would force a revisit to the tuning issues.
As always YMMV. See http://n6mw.ehpes.com for details - at the end of
the antenna project list.
Bill, N6MW
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Topband Reflector
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