Well, after many years of wishing, it looks like 2012 will be the year I
finally get a tower and yagi added to my station. After many years with
multi-band verticals and relatively low wires this is a much anticipated
enhancement. More than likely with will be the one and only tower I will
be able to install.
I do not have any experience with towers, and would value your inputs on
my thinking below.
I would very much like to install a Steppir DB-36 on a tower of at least
70 feet. I know, higher would be better, but the next increment in
height seems to entail a disproportionate increase in cost. After all
these years, I really would like to have gain antennas on 40 and 30
meters. Per Steppir, the DB36 is 17.5 sq ft, 160 lbs.
After a lot of soul searching, I have to admit that I am in no shape to
be climbing towers, and this is not likely to change. And there is not a
strong local climbing ham population to assist.
So, a crankup/tiltover tower (with NN4ZZ tiltplate) seems to be the only
solution. The only towers that look even close are the US Tower HDX-572
or the Tashjian DX-70.
I am fortunate to live in a rural area with no zoning or permitting
requirements. I can put up any foolish thing I want. <grin>
Today I was able to obtain an engineering analysis for the HDX-572 and
was disappointed to learn that the Windload is limited to 14.1 sq ft
(exposure B, 90 mph 3 second gust, 76mph fastest mile.)
The Tashjian DX-70 shows a spec of 47 sq ft (85 mph 3 second gust).
Clearly this will be adequate (if not somewhat over designed - which is
not a bad thing). Of course, the DX-70 initial quote I have about $1K
more than the HDX-572. IT would certainly seem that the increased
capacity is worth the greater initial expense.
Can anyone help by contributing their experience with a DB36 (or similar
large antennas) on a crankup in the 70 foot (or taller) class?
Many thanks and 73;
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