John, your same question was asked about a year ago on this list regarding what
tower to use for a DB-36. I have an UST HDX-772MDPL (spec: max load 700lbs,
70sq ft @ 70mph) with a SteppIR MonstIR and F12 Sigma-280 Magnum mounted, so
yes UST does have additional special order towers available--just not listed in
their catalog or on their website. Mine is based on their HDX-5106 design,
minus the top two sections. Call UST and talk with them regarding your needs.
Gary NØGS
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of John Kuklewicz N7ZN
Sent: Friday, January 27, 2012 3:54 PM
To: Tower Talk List
Subject: [TowerTalk] Crankup Tower for DB-36
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;
John N7ZN
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