On 05/30/2010 05:44 AM, Gary K9GS wrote:
> So Chris....is the Spiderbeam mast for sale?? I'm looking for something to
> use to build an 80M vertical......
>
For a vertical, you probably don't want the aluminium mast, but their
fiberglass pole, at a fraction of the cost. They come in 12, 18 and 26
meters. You can use the whole length for a vertical. To support an inv
vee, I leave out the top 2 or 3 sections. For a yagi, you'd better use
an aluminium mast.
73
LA4RT Jon, Trondheim, Norway
>
> 73,
>
> -Gary K9GS
> GMDXA Web Site: www.gmdxa.org
>
>
> ----- Original Message -----
> From: "EZ Rhino"<ezrhino@fastmovers.biz>
> To:<w1nk@cox.net>
> Cc:<towertalk@contesting.com>
> Sent: Saturday, May 29, 2010 12:05 AM
> Subject: Re: [TowerTalk] TA32M& Spiderbeam Push Up Mast
>
>
>> Hi Frank,
>>
>> It seems like a feasible plan. I have a little bit of experience with the
>> SpiderMast, so I can offer some insights.
>>
>> It is a well built unit, and quite solid when raised. Its big advantage
>> is the portability. It fits inside an 8" square box about 4' long. It's
>> big downfall is the major PITA to get an antenna raised on it. (It's also
>> not particularly cheap).
>>
>> I have set up a 5 band SpiderBeam on a 50' Spidermast at Field Day and
>> 7QP. The reason it is hard to erect is the increasing weight when pushing
>> each section of mast up. At first it isn't that bad, but it becomes
>> increasingly heavier the taller it gets. It becomes impossible (unless
>> you are Mr. T or Arnold the Governator) to hold with one hand while
>> tightening the clamps with the other to keep the section just raised in
>> place. It really requires two people. Also, the mast when fully
>> collapsed is 5-ish to 6 feet tall, which means you need to stand on a
>> ladder placed right next to it in order to be tall enough to raise each
>> section. This puts you at an awkward angle leaning over to muscle each
>> section up. Another difficulty is when you push up a section, the entire
>> mast wants to raise (or come off the ground) because of the close
>> tolerances (friction) from tube to tube. Finally, the three guys need to
>> be continually slackened as the mast goes taller. This is really tri
>> cky if it is windy.
>>
>> My buddy devised a clever system of using a farm jack (hi lift jack) to
>> jack up each section, making the raising somewhat easier, but creates a
>> new set of problems that I won't go into here. So it takes a minimum of
>> 45 minutes to get it airborn, and then you run an SWR check and realize
>> the antenna needs tuning and then you let it down and start all over.
>> hihi. One advantage is you can get it completely down in a couple
>> minutes.
>>
>> We threw in the towel after 7QP this year and pulled the trigger on a
>> Universal aluminum tower, 4 sections, 40' tall. With a mast it will be
>> between 45-50 ft. Each tower section is tapered and nests inside the
>> largest section, making transporting it fairly easy in a pickup truck. (4
>> sections weigh 85 pounds). Currently I'm getting it ready for Field Day.
>> I'm building a hinged base out of 2x6's and it will be guyed (obviously)
>> at the top. The mast will have a hinge on the top which will allow the
>> antenna placed on it horizontal to the ground when the tower is laying
>> flat, then can be brought to horizontal when the tower is stood up. We're
>> going to use a modified falling derrick method of raising it.
>>
>> Chris
>> KF7P
>>
>>
>>
>>
>>
>>
>> On May 28, 2010, at 12:57 ,<w1nk@cox.net> wrote:
>>
>> Can anyone find anything wrong with my plans?
>>
>> I would love to put up my (stored) TA32M but would prefer avoiding the
>> expense, etc of a tower. I happen to be looking over the Spiderbeam
>> website and came across their aluminum push up mast ("heavy duty"). The
>> mast is 7 sections ranging from 2.75" at the bottom to 1.5" at the top.
>> Wall thickness is 2mm.
>>
>> According to the manufacturer this mast will support the heavy duty
>> Spiderbeam which has the following specs:
>> Boom: 33 ft
>> Turning Radius: 16 ft
>> Wind Load: 3.8 sq-ft
>> Weight: 23lbs.
>>
>> According to the Mosley website, the TA32's specs are nearly identical.
>>
>> The setup would be guyed (obviously) using 2 ft ground stakes
>> (Spiderbeam's) or 4 ft ground screws (DxEngineering). The rotor would be
>> a base mounted HD73 (also in storage and refurbished about 15 years ago).
>>
>> So, tell me my thinking is too good to be true. Or for that matter if I
>> have a workable setup.
>>
>> Frank, W1NK
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