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Re: [TowerTalk] AB-577

To: "Tower and HF antenna construction topics." <towertalk@contesting.com>
Subject: Re: [TowerTalk] AB-577
From: van wd8aam <vlincoln@frontiernet.net>
Reply-to: "Tower and HF antenna construction topics." <towertalk@contesting.com>
Date: Tue, 20 Apr 2010 06:53:39 +0000
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
No, not removed, the ebay auction is still there.

go to this link:  http://tinyurl.com/y6xx9uh

van wd8aam

At 06:41 4/20/2010, you wrote:
>The item has been removed from ebay. No explanation  provided.
>ebay may read this thread.
>73's chris kf7cob
>
> > I have three AB-577s, one with a homemade (to spec) extension kit, so I'm
> > quite familiar with them.
> >
> > There are a few odd things about the one listed on ebay, so I would urge
> > caution for anyone interested in buying it.
> >
> > First and most important, you should know that the stock mast goes to 48
> > feet, not 60'. The kit offered for sale appears to be an incomplete
> > collection of parts from two or more AB-577s that have been put together
> > to
> > get the extra height. The stock guy anchors are installed 30 feet out,
> > which
> > is the default distance measured by the supplied measuring rope. It's
> > already pretty close for a 48-footer (60% of height), and in my opinion
> > way
> > too close for a 60-footer. I would push the guys out to at least 40', if
> > not
> > 50' (the rope can also measure that distance because it's used for the
> > extension kit -- see below.) Even then, I doubt the mast would meet its
> > original engineering specs at 60 feet with only three guy sets. The clamps
> > used to mate the tubes are not very rugged and can't take a lot of lateral
> > force. The greater the distance between the guys, the more lateral force
> > will be on the clamps. Also, it may be very difficult, or even hazardous,
> > to
> > erect the unit with that much distance between the guys. Before final
> > tension is applied, the mast behaves much like a wet noodle. The greater
> > the
> > vertical distance between the guys, the more exaggerated this effect will
> > be. This tends to get worse the larger the antenna.
> >
> > It appears that the original installation manual does not come with this
> > unit. I would urge anyone buying it to get a copy of the manual and read
> > it
> > carefully (there are probably some scans online.) The installation
> > procedure
> > should be followed to the letter to ensure safety of all personnel and
> > equipment.
> >
> > Additional information:
> >
> > The stock AB-577 comes with eight 5-foot tubes, which is the maximum
> > number
> > the portable carrier will hold. The five tubes with the 8-foot launcher
> > gives you 48 feet. It also comes with two different guy rings, one for the
> > top guys and one for the middle guys, plus an antenna adapter. The three
> > guys anchors are installed 30 feet from the base.
> >
> > The extension kit comes in its own plastic carrying case (that's the one
> > piece I don't have.) The kit adds five more tubes, for a total height of
> > 73'. Also included are an additional guy ring, two more guy sets and three
> > more screw-in guy anchors. The stock bottom and middle guys remain at
> > their
> > stock positions and still run to the stock anchors 30' out. The longer of
> > the two new guy sets replaces the stock top guy set. The other guy set is
> > installed halfway between the top and stock middle guy, using the
> > additional
> > guy ring. The two new guy sets attach to the extension anchors, which are
> > installed 50 feet out. So you end up with four sets of guys, the lower two
> > sets anchored at 30 feet out and the upper two sets anchored at 50 feet
> > out.
> >
> > The non-standard height of the unit for sale on ebay, and the fact that it
> > comes with two launchers, two carriers and three middle guy rings, makes
> > me
> > suspect that it's a combination of at least two AB-577 sets. It appears to
> > be missing two standard parts: the top guy ring and the antenna adapter.
> > Without those parts, one of the middle guy rings would have to be used for
> > the top guys, and that would require putting an unguyed tube above the top
> > guy ring. It's not safe to put an antenna at the top of that (again, the
> > ring clamp can't take the lateral force), so the antenna would have to be
> > placed at the bottom of the top tube with some sort of homemade adapter
> > (the
> > stock antenna adapter has a short piece of ~2" mast welded to it that's
> > perfect for mounting an antenna bracket or a rotor bottom bracket.) I
> > think
> > this might explain the discrepancy between the description, which says it
> > comes with 11 tubes, and the parts list which says it comes with 12 tubes.
> > The top tube, for all intents, gives you no additional height.
> >
> > The unit is also lacking the canvas roll, used for storing and carrying
> > the
> > anchor stakes, sledge hammer and claw bar (the latter two also appear to
> > be
> > missing, but that's not unusual). It's also missing the canvas bag used
> > for
> > carrying the guys sets, rings, clamps, etc. I don't see the "winch
> > spanner"
> > listed, either. This is a special tool that can be used to rotate the mast
> > after it's been erected (the guy rings slip to allow this.)
> >
> > The original AB-577 guy sets came with 1/8" stainless steel guys.
> > Refurbished models usually have plastic-coated galvanized aircraft cable.
> > Stainless guys work better with the "snubbers" used for tensioning the
> > guys,
> > but the plastic-coated guys do work (my two 48-footers have plastic guys
> > but
> > someday I'll replace them with stainless.)
> >
> > As for the price, I'd certainly pay $650 for a complete 48' kit, but it
> > really depends on the condition of the parts, especially the clamps, which
> > tend to wear out with repeated use, and the guy sets. The collection of
> > parts offered on ebay is probably worth $650-$800 if the parts are in
> > decent
> > condition --  the extra launcher, tubes and middle guy rings are worth
> > money
> > for sure. But I'd look into sourcing as many of the missing parts as
> > possible, specifically the top guy ring and antenna adapter. If the plan
> > is
> > to take it over 48', I would also get three additional screw-in anchors
> > and
> > an additional long guy set (or make one using the snubbers from a shorter
> > guy set.) Ontario Surplus (http://www.ontariosurplus.com/ab577.htm) has
> > most
> > of the missing parts in stock. They also have a few complete 48' kits
> > available, so you can compare the price.
> >
> > 73, Dick WC1M
> >
> >> -----Original Message-----
> >> From: Neil & Heather [mailto:neil.goodell@myfairpoint.net]
> >> Sent: Monday, April 19, 2010 5:15 PM
> >> To: TowerTalk@contesting.com
> >> Subject: [TowerTalk] AB-577
> >>
> >> http://cgi.ebay.com/60foot-Plus-all-aluminum-
> >>
> > 
> tower_W0QQitemZ250618401345QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3a
> > 5
> >> a055241
> >>
> >> These are getting harder and harder to find.....
> >> posted for those interested.....
> >>
> >> 73
> >> Neil
> >> AE1P
> >
> >
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
>
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