Ron,
I have 2 each of those three antennas, spread over two towers, at heights
from 50 ft to 141 ft. See: www.erols.com/n3rr
I live in an area where the wind is funneled down into a trough and blows in
from the west to east. We regularly get 50 - 70 mph winds in season (now),
and in a storm are much higher.
All of my HG antennas (105CA, 155CA, 205CA) (except my 205CA @ 50 ft which
is not reinforced at all) are reinforced per the W6QHS (++) design (elements
and boom). The boom reinforcements raise the boom survival to:
105CA = 150 + MPH
155CA = 139 MPH
205CA = 124 MPH (also, triple-guy design raises that to 157 MPH) (I don't
use the triple-guy arrangement).
Three of them are mounted in Ring Rotors, three use the HG clamp on a mast.
Both 205CAs have boom trusses.
I venture to say that if you reinforced your elements and boom per the W6QHS
(++) design (per his book: The Physical Design of Yagi Antennas, published
by ARRL), you will be fine in the future.
73,
Bill, N3RR
----- Original Message -----
From: "Major Ron" <majrabsr@rconnect.com>
To: <n8de@thepoint.net>
Cc: <towertalk@contesting.com>
Sent: Monday, February 11, 2002 6:32 PM
Subject: Re: [TowerTalk] Antennas down
>
> OK Don (and All),
>
> The antennas were stacked in 'normal' Christmas tree fashion. There was
> about 1/4" to 3/8" (measurements were taken on the ground AFTERWARDS) of
ice
> after the freezing rain, which then turned into heavy wet snow. There were
> no compensators on the antennas and they were pointed into the wind. Winds
> were steady at 55-70MPH with gusts reaching 90MPH. ALL elements failed at
> the swage points. 20M boom broke on one side of the re-inforcement at the
> center near the mast. 10 & 15m booms bent at the same point. One side of
the
> driven element on 15 & 20M beams broke at the insulators. Several element
> pieces (don't know which antenna they came from yet) appear to be twisted
> radially.
>
> I really am amazed that the T6 escaped any damage at all. Its elements
were
> sagging badly and waving around in the wind when I last looked at them,
> while the HG antennas elements appeared to be handling everything pretty
> well. I took a rest break from the contest and went to bed to find this
mess
> of aluminum laying on the ground when I awoke and couldn't tune the
> antennas.
>
> I have to figure out something different because I cannot afford this to
> happen again.
>
> 73,
> Ron, KA9ALC
>
> ----- Original Message -----
> From: "Don Havlicek" <n8de@thepoint.net>
> To: "Major Ron" <majrabsr@rconnect.com>
> Cc: <towertalk@contesting.com>
> Sent: February 11, 2002 21:40
> Subject: Re: [TowerTalk] Antennas down
>
>
> > Ron
> > Educate us!
> > What was the orientation of those antennas to the wind direction when
> > they 'failed' the stress test?
> > What was the amount of radial ice on them?
> > Were they stacked in a Xmas tree?
> > If so, was the Xmas tree 'ordinary' or 'inverted'?
> > Where did the 205CA boom fail?
> > Where did the 155CA boom bend?
> > Where did the 105CA boom bend?
> > Which elements on which beams failed?
> > Did you have 'compensators' on the booms?
> > Very interested in the answers to these questions, as I am about to
> > erect an 'inverted' Xmas tree of 20 over 15 over 10 .. 204BA instead of
> > 205CA.
> > Thanks in advance.
> > Don
> > N8DE
> >
> >
> > Major Ron wrote:
> > >
> > > We here in SW MN had freezing rain and high winds SAT night & SUN
> morning.
> > > My HyGain 205CA, 155CA and 105CA are history. Broken elements on all
of
> them
> > > and broken boom on 205. 155 & 105 booms are severly bent. Guess I'll
be
> in
> > > the market for some new antennas after I find a new job. Only
surviving
> beam
> > > is Tennadyne T6.
> > >
> > > Ron, KA9ALC
> > >
> > >
________________________________________________________________________
> > > Where do you get ICE bandpass filters & beverage matching boxes? The
> > > same place that pays for the hosting of this list: The eHam Store.
> > > Order online at http://store.eham.net.
> >
> -----------------------------------------------------------------------
> > >
> > > -----
> > > FAQ on WWW: http://www.contesting.com/FAQ/towertalk
> > > Submissions: towertalk@contesting.com
> > > Administrative requests: towertalk-REQUEST@contesting.com
> > > Problems: owner-towertalk@contesting.com
>
>
> ________________________________________________________________________
> Where do you get ICE bandpass filters & beverage matching boxes? The
> same place that pays for the hosting of this list: The eHam Store.
> Order online at http://store.eham.net.
> -----------------------------------------------------------------------
>
> -----
> FAQ on WWW: http://www.contesting.com/FAQ/towertalk
> Submissions: towertalk@contesting.com
> Administrative requests: towertalk-REQUEST@contesting.com
> Problems: owner-towertalk@contesting.com
>
>
________________________________________________________________________
Where do you get ICE bandpass filters & beverage matching boxes? The
same place that pays for the hosting of this list: The eHam Store.
Order online at http://store.eham.net.
-----------------------------------------------------------------------
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|