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Re: [TowerTalk] Mast recommendations?

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Mast recommendations?
From: Bryan Swadener <bswadener@yahoo.com>
Date: Tue, 4 Jun 2013 21:50:01 -0700 (PDT)
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
I like my 40' tilt-up rotatable mast, easily made from
inexpensive 1-1/4" Schedule 40 steel pipe + various 
fittings.   Some simple welding is required.  Using a 
falling derrick, one person can easily & safely tilt
it up/down. A few bodies make it go faster.  I've
used it several times since the early 1990s.

An 80m cage inverted vee and a 40m inverted vee
form the top guys. BW on 80m is almost 400 KHz, and
we tune it for 3500 to 3900 KHz. With a tribander
on top, it covers 80-40-20-15-10m.

Rob, see my links to drawings, detailed construction
info, photos, and a video clip (sent privately).

vy 73,
Bryan WA7PRC

 
> Date: Tue, 4 Jun 2013 18:47:57 -0700
> From: Dick W1KSZ
> 
> I remember seeing a ladder used as the support. Probably
> easier to
> walk up than a single mast.
> 
> 73, Dick, W1KSZ
> 
> 
> On Tue, Jun 4, 2013 at 6:09 PM, K8RI wrote:
> 
> > On 6/4/2013 8:19 PM, Robert Fanfant wrote:
> >
> >> Our field day team is planning to put up a SteppIR
> 2 element yagi (~25
> >> pounds). We'd like to mount the yagi  ~20-30
> feet high and would like mast
> >> recommendations.  This is only a field day
> (i.e. once a year) event so cost
> >> is a factor, yet the mast should be strong enough
> so that we aren't out the
> >> price of a replacement antenna. Our field day
> location will be in eastern
> >> WA where we at times tend to get moderate winds
> (~10-20mph) coming through
> >> our campsite. Thoughts?
> >>
> >>
> > Can this be one piece, or does it have to be in
> sections?
> > If you have a nearby metal supplier, you can purchase
> tubing, either
> > structural steel or pipe.  Structural Tubing comes
> in schedule 40 and 80
> > just like pipe and is rolled with a welded seam
> >
> > I purchase the tubing in steel and Aluminum.  The
> Aluminum is drawn and
> > seamless. It comes in a variety of alloys and wall
> thickness.  For what you
> > want 1/8th inch wall should suffice in 6061-T6. 
> There are stronger alloys
> > if you wish and I purchase 1/8th, 3/16ths, and 1/4"
> wall.  The only
> > drawback to this is, standard sizes do not easily
> telescope.   The steel is
> > also available as DOM.  However as cost is an
> issue, we can pretty well
> > rule out DOM.
> >
> > All are sold by the pound.
> >
> > It's been quite a while since I purchased a load og
> steel and aluminum so
> > I don't remember the prices which would be out of date
> anyway.
> >
> >  -Rob N7QT
> 
> 
> Date: Tue, 04 Jun 2013 20:54:20 -0700
> From: Jim Lux
> 
> A couple lengths of pipe with a coupler or lots of duct tape
> might work. 
> Armstrong rotator?
> 
> 
> A 30 foot extension ladder (you can rent them pretty cheap)
> is another 
> good way. You can lash a rotator to it, it walks up pretty
> easily as 
> long as you have 3 or 4 people, and guy it with ropes and
> stakes.
> 
> Check your local rental yard.. they have all kinds of stuff
> that might 
> work out real well for you.
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