In article ,
engsol wrote:

Oh boy..here we go...laughing.... see below....


snipped for brevity

Bruce has an excellent point re the windings...but I see a problem.
Given a kelvar backstay length, how would one compute the
pitch of the wrap? A turn every 6 inches for the first 2/3rds? Then
every 2-3 inches for the remainder? Ouiji board?

This topic is so interesting to me that short of buying a network analyzer,
(I'll be honest, I can't afford one), I'm determined to figure out what
simple test equipment I can use to evaluate various configurations,
and then test them.
Any ideas?
Norm B


Actually most of the work in this area was done by Ed Zanbergen, while
he was Principal Partner and Chief Engineer of MORAD Electronics in
Seattle, Wa. MORAD antennas are the defacto standard for commercial
vessels in the North Pacific. They build some of the most rugged and
effective antennas in the Marine Mobile Radio Service. Ed is long since
gone to the Great Radioroom in the Sky, but his legacy is still around
and being produced by MORAD today. When I was a beginner in this bizz,
I worked for Northern Radio Co. which had a shop next door to Morad,
and Ed and I became very good friends. I still have some custom antennas
that he built for me, specifically for MF/HF Coast Station installations
in alaska. I don't know if any of his notes were ever published, but
he spent 40 years designing antennas in these Radio Services.

One of the better designs that Ed built for me was a pair of matched
Helically Loaded Whips that were resonate at 3300Khz. I mounted them at
60 Ft in a Dipole configuration, with PhosBronze feedwire, connected at
the end of the 15 Ft Base tubes. Then feeding down to an Experimental
SEA 1612B Autotuner that has twin tuning boards driven by a single CPU/
Sensor System, so that both dipole legs are effectivly tuned by the
autotuner. This antenna can be heard, evey summer on the Marine Freqs
as KWO-70/WDT-59 and operations on all Marine Bands from 2003Khz
to 25 Mhz.

Bruce in alaska
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