I should mention that the AB-577 has a big brother: the AB-621/G. I've seen
the manual. The design is very similar, but the 621 is a lot beefier and
weighs more -- it would take 3-4 people to haul it around in one piece. The
launcher is wider and heavier, and the sections are 6" diameter tubing
that's swaged so the sections fit into each other instead of being connected
with steel spring clips like the 577. There's enough overlap for the mast to
be much more stable during erection before the guys are tightened. I've
never put one up, but my guess is that one person could raise a 50' 621 with
a yagi on top in a stiff breeze. I don't know the windload capacity, but I
would guess it's considerably higher than the 577. Last I checked, Ontario
Surplus has some 50' AB-621/G kits, but they may not have all of the parts
like full guy sets, etc.
There's also an extension kit that takes the 621 to 100'. The kit includes
ratcheting guy spools that you mount on the ground. Basically, these devices
pay out the guy cable as you raise the tower, keeping constant tension on
the mast. It appears to me that with these devices one person could easily
raise the 100' version, even with a big antenna and the wind blowing
moderately. It's an amazing design. Unfortunately, no one has these kits for
sale and no one in the surplus or ham market has ever seen one of the guy
spool devices. Perhaps they were made in very small quantities or the army
still has most of them in use.
73, Dick WC1M
> -----Original Message-----
> From: David L. Thompson [mailto:thompson@mindspring.com]
> Sent: Friday, June 27, 2003 9:42 AM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] Portable Tower Question
>
>
> Don't forget about the portable tubular crank ups sold by
> Force 12. They are more expensive than the AB-577 but much
> lighter and smaller.. A friend has the 42 foot version
> mounted on the rear of his big Van.
>
> Another option is the complete tower and trailer sold by
> Alumna tower..this does run $6,000.
>
> Military surplus towers (both tubular and smaller versions
> similar to the
> AB-577) are often sold by military surplus dealers. There is
> a fellow in Roswell, GA who sells a 30 foot version of the AB
> tower for about $350 when he has them. I understand they are
> often for sale on Ebay under both amateur radio and military.
>
> I find the 4 or 5 foot section aluminum and fiberglass tubing
> sections are hard to work with when more than 5 or 6 sections
> are placed together. Years ago I had 50 feet (10 sections)
> of 1 3/4 aluminum tubing from a WW II TBW 5 set that we used
> on field day to hold a G4ZU birdcage and a Gonset 20 meter
> bow tie beam. Fairly easy to get up with two or three people
> helping but impossible to take without help And we only went
> up 6 sections! The instructions said to have a muscular
> marine hold the center, another marine to add sections and
> three marines to hold the guy lines. This for a double
> doublet. They had two towers to put up.
>
> 73 Dave K4JRB
>
>
>
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