[Elecraft] Vertical doublets

[Allen Ward]

For about the last 17 years I have been using a 20 meter groundplane
vertical and a TenTec 229 tuner on 40 - 10 meters with very good results
with QRP and 100 watt level.  Fed with open wire it WILL TUNE over the
range.  I built this long before the Cebik article, which by the way if you
read carefully says that such an antenna will be about as good as the
doublet.  When I finially read Cebik I modeled the doublet vs the
groundplane and there is very little difference.  I use a 16.5 ft aluminum
tubing vertical at 10 feet and four 17 ft wire radials drooping about a foot
at the ends.  One could also use 22 ft (to duplicate the doublet) however my
modeling shows that the shorter antenna gives better results on 17 to 10
meters.  Not being an intense DX'er  I have managed about 200 countries over
the years with more or less random efforts and hunt and pounce during
contests.
I see no need for multiple length radials and of course 8 or 16 radials
would probably be worthwhile.  Your ground conditions have an effect.  I was
blessed with an excellent ground of deep sandy loam for 1/4 mile in all
directions.  One thing is that a groundplane is easier to build than a
vertical doublet.  Bye the by I use 150 plenum twinax (Belden 9182) for
feeding the antenna.  This has about the same loss as RG-8 so I only use 30
feet.  Works well and is not disturbed by rain etc.  I have often considered
a different antenna but the simplicity, cost and ease of erection keep me
with this one "all-bander."
Allen KA5N