Topband: Linear Loading & 160-Meters
dick-bingham
dick-bingham at hughes.net
Wed Feb 24 08:27:07 PST 2010
Good morning everyone!
Regarding the comments on "Subject: Re: Topband: "Linear Loading" &
160-Meters",
I did not see any comments about the use of 'full-size' elements for the
'Bob-Tail' and
'Half-Square' antennas where the horizontal 'top' phasing wire is at, say,
80/90 feet.
I have been using sloping end-wires in my version of a "Half-Square" (horiz
top wire ~80ft)
and it has been my best-ever 160-Meter antenna. A simple 'no-brainer' but
highly effective
antenna! No multi-wire radial ground system required unless you think a
single ground-rod
hammered into rocky/sandy soil at the antenna feed-point is 'extensive' !!
Yes, the sloping H-S does favor the direction towards the 'sloped-end'
(modeling indicates
about 3dBi forward and 1dBi reverse direction gain) but from here in
WA-State I get great
coverage of the USA and have worked SM and have been heard in "G" and "DL"
land using
100-watts.
As an aside, VK6VZ's two sloping isolated delta-loops (apexes slightly
spaced but
supported from a central support @94ft and their outlines look like a
skeleton 4-sided
pyramid) use linear-loading in each base-leg. This more complex but still
'simple' antenna
models-out at about 1db less gain than the sloping H-S but has wider -3dB
gain beamwidth.
If you have the 'room' to slope your wires but insufficient 'height', I
would highly recommend
the 'Sloped' version over a so-called linear-loaded H-S or Bobtail array...
73 Dick/w7wkr CN98pi
More information about the Topband
mailing list