The Woodbridge Wireless ARC have used the AB-577s in countless portable
operations. We do not put them up without a piece of steel pipe (I'll try
to find out the size) which fits inside the top stub. It is held in place
by a treaded rod through the pipe which rests in the two U shaped grooves on
the top of the stub. The pipe extends down into the top tube about a foot
or so. This not only adds some strength to the top stub for mounting the
lower rotor clamp but also provides an added measure of safety if the top
guy ring were to fail. This will not allow the antenna, rotor and mast to
fall completely off the top of the AB-577. Instead, the steel pipe would
only get cocked over inside the top tube but would still allow the tubes to
be lowered safely for repair. Pete, I'll see if I can get a picture of one
of the pipe inserts when I go back to the club trailer in a week or so. You
could also contact Stu W7IY to see if he has any pictures.
73, Jack W4NF
-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of
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Sent: Thursday, July 28, 2022 12:00 PM
To: towertalk@contesting.com
Subject: TowerTalk Digest, Vol 235, Issue 27
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Today's Topics:
1. AB-577 top stub (Pete Smith N4ZR)
2. Long Term Connector Reliability (jim.thom jim.thom@telus.net)
3. Re: AB-577 top stub (Pete Smith N4ZR)
----------------------------------------------------------------------
Message: 1
Date: Wed, 27 Jul 2022 12:32:25 -0400
From: Pete Smith N4ZR <pete.n4zr@gmail.com>
To: TowerTalk <TowerTalk@contesting.com>
Subject: [TowerTalk] AB-577 top stub
Message-ID: <ba99cae1-5335-bae4-0844-ececc6a90b1a@gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
This is pretty speculative, so if anyone wants to erase now...
My AB-577 (the first and only one I've ever been up close and personal
with) has a short stub of tubing that is integral with the top guy
connection, and on which my C-3 mounts nicely .? If I want to stack a
6-meter yagi on top of my existing tribander, I suspect that the best way to
do so would be to telescope the bottom end of 6 feet or so of tubing inside
the stub and put a bolt through to hold it both vertically and in rotation.?
Just by chance, has anyone ever measured the inside diameter of that short
stub (assuming that it is, in fact, part of the standard AB-577)? I'd hate
to get the rocket launcher all the way down, only to find that the mast
extension I will have selected is either too small or too large.
--
73, Pete N4ZR
Check out the new Reverse Beacon Network web server
at<https://reversebeacon.net>.
For spots, please use your favorite
"retail" DX cluster.
------------------------------
Message: 2
Date: Wed, 27 Jul 2022 10:21:29 -0700
From: "jim.thom jim.thom@telus.net" <jim.thom@telus.net>
To: towertalk@contesting.com
Subject: [TowerTalk] Long Term Connector Reliability
Message-ID:
<CAB4ZMgs-YzKMiQ7CyEyuXbAKkpaX=vHPYdt6isD6fvZCtZCh2Q@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Permatex dielectric grease works superb on the threads of coax
connectors....and just a tiny, ultra thin layer on the center pin of the
male plug.
On bigger cables, like LMR-1200DB, and 7/8" heliax etc, the only
connectors that are available are type N..and 7-16 DIN. I gave up on
Type N years ago. Everything here is 7-16 DIN. Smaller cables like
213-U use UHF connectors. RG-393 uses 7-16 DIN.
A type N connector on LMR-1200DB, or 7/8" heliax looks pretty silly, with
it's puny BNC sized pin.
Make sure any connector is the silver plated type, with teflon dielectric.
Jim VE7RF
------------------------------
Message: 3
Date: Wed, 27 Jul 2022 22:00:25 -0400
From: Pete Smith N4ZR <pete.n4zr@gmail.com>
To: "Joe Subich, W4TV" <lists@subich.com>, TowerTalk
<TowerTalk@contesting.com>
Subject: Re: [TowerTalk] AB-577 top stub
Message-ID: <5dde906b-52c6-9b6d-53d1-6f5a63f6c055@gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Duhhh - I apologize for the stupid question.? I don't know what I was
visualizing. Of course, what you describe is exactly how it works in my
case, and I will simply need to substitute a longer piece of mast tubing
in the upper clamp of the rotator.? Easy peasy.
73, Pete N4ZR
Check out the new Reverse Beacon Network
web server at<https://reversebeacon.net>.
For spots, please use your favorite
"retail" DX cluster.
On 7/27/2022 1:52 PM, Joe Subich, W4TV wrote:
>
> > My AB-577 (the first and only one I've ever been up close and personal
> > with) has a short stub of tubing that is integral with the top guy
> > connection, and on which my C-3 mounts nicely .
>
> How/where are you mounting your rotator?
>
> The "top stub" ("Antenna adapter" 80063; SM-C-423587) - shown in Fig
> 1-4, and Fig 2-12 in the "manual".? The bottom of the rotator "pipe
> mount" clamps to it (it's just over 2" outside diameter) with the mast
> clamped into the top of the rotator and antenna mounted to the stub
> mast above the rotator.
>
> I'd use a 6' piece of 2" x .120 tubing for the mast with the C3 as
> close to the top of the rotator as possible with a 3 or 4 element
> 6m yagi 5' above the C3.
>
> 73,
>
> ?? ... Joe, W4TV
>
> On 2022-07-27 12:32 PM, Pete Smith N4ZR wrote:
>> This is pretty speculative, so if anyone wants to erase now...
>>
>> My AB-577 (the first and only one I've ever been up close and
>> personal with) has a short stub of tubing that is integral with the
>> top guy connection, and on which my C-3 mounts nicely .? If I want to
>> stack a 6-meter yagi on top of my existing tribander, I suspect that
>> the best way to do so would be to telescope the bottom end of 6 feet
>> or so of tubing inside the stub and put a bolt through to hold it
>> both vertically and in rotation.? Just by chance, has anyone ever
>> measured the inside diameter of that short stub (assuming that it is,
>> in fact, part of the standard AB-577)? I'd hate to get the rocket
>> launcher all the way down, only to find that the mast extension I
>> will have selected is either too small or too large.
>>
------------------------------
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