I wish to thank all who have responded regarding length of the Beverage.
Most recommend limiting the extended length to about 580' as the best
compromise between lobe width and f/b ratio. I could easily go as long as
715', but any extension must wait till the farmer who leases the land has
finished for the season.
The "cone of silence" issue brings up another topic. I first heard of the
term in W1WCR's Beverage antenna book. I recall that ON4UN makes a few
references to W1WCR's publication in his own book. However at least three
things in W1WCR's book cast doubt on the entire work.
(1) He claims that for 1.8 mHz and above, the ground systems at each end of
the antenna should be bonded together with an insulated wire lying on the
ground directly under the antenna wire for its entire length. This seems
contrary to anything else I have ever read about Beverage theory.
(2) He recommends sloping each end of the antenna to reduce pickup from the
vertical drop. Don't you have exactly the same vertical drop, regardless of
whether it occurs at one point, or over a length of 50 or 60 feet? To me,
this is somewhat like saying it takes less energy to move an object up a
gradual incline than to use a vertical lift up the same elevation
(neglecting friction, the energy expenditure is exactly the same).
(3) All the rf transformers he shows are autotransformers, grounded at one
point, with a tap for the coax feedline. With any antenna of this kind,
including the K6STI loop, the flag, ewe, etc., the recommendation is always
to use a transformer with separate primary and secondary and
electrostatically shielded if possible, with the bottom end of transformer
secondary strapped to the coax shield but NOT grounded to the same point as
the primary. The purpose of this configuration is to avoid common mode
noise pickup. These three questionable items make everything else in the
book suspect, even though at first glance most of it appears to be based on
sound principles.
Again, I would be interested in hearing other more seasoned opinions on this
topic. I am relatively new at topband receiving antenna design. Although I
have been active on the band for over 40 years, until recently, I mostly
used it for ragchewing over distances of 500 miles or so, using my
transmitting antenna or a simple indoor loop for receiving, with everyone
running relatively high power. In the past 7-8 years, the stations I used
to talk to have fallen by the wayside, one at a time, until most of my
"ragchew" contacts are now 800-1200 miles away, largely in Northeastern USA.
At the same time, local electrical noise seems to have become
substantially worse as suburban sprawl has invaded our area, so for the past
few years, I had become less active an 160 because everyone in North America
seemed to hear my quarter wave vertical extremely well, but I couldn't hear
the stations who called well enough to maintain comfortable contact. This
past winter I put up a Beverage and K6STI loop. The loop was a
disappointment, but the Beverage allowed me to hear the stations in the
Northeast often armchair quality. Up to last winter, I could probably have
counted all the topband DX stations I had ever heard on one hand, and the
ones I had actually worked on a couple of fingers. With the Beverage, I
could hear CW stations in Europe with no problem when the band was open
(even worked a few). If I can achieve decent receiving capability, I'll
undoubtedly become more active on the band, both ragchewing and working DX.
73, Don K4KYV
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