[TowerTalk] IPInning the mast errata
Jon Casamajor
k6el at comcast.net
Thu Mar 12 20:22:57 PDT 2009
Interesting discussion and it seems relative to what you live with in terms
of wind, how large your stack is and how willing you may be to realign your
stack. I pinned my KT34-XA and 402CD stack originally and ended up with a
busted tower brace below the thrust bearing and above the T2X. I have not
pinned it since, probably 15 years and have only realigned the stack once
after a particularly nasty storm. My new stack has not shifted in 8 months.
I've learned how to park it which helps.(see it at QRZ) I guess I would
rather realign it then have to either repair the tower or replace the rotor.
Personal choice I guess. I'm getting too old to start over! :)
> Well, without being pinned, it would probably move harmlessly out
>of alignment. When you pin a mast to a rotator you're transferring the
>mast torque directly to the rotator and the next weak point in the
>system; usually gears.
>
Regards,
Jon Casamajor
k6el at comcast.net
-----Original Message-----
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Sent: Thursday, March 12, 2009 11:39 AM
To: towertalk at contesting.com
Subject: TowerTalk Digest, Vol 75, Issue 29
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Today's Topics:
1. Re: Pinning my mast in rotator clamp (K7LXC at aol.com)
2. Re: Pinning my mast in rotator clamp (W3YY)
3. (no subject) (W0MU Mike Fatchett)
4. 80m 4 sq shortened vs full sized (W0MU Mike Fatchett)
5. Anchoring of guy wires (Kjeld Holm)
6. Re: Pinning my mast in rotator clamp (Pete Smith)
7. Re: Pinning my mast in rotator clamp (Pete Smith)
8. need some help with 4130 material.... (Chris Davis)
9. Parts fo A HAM II (J. Wolfe)
10. Re: Pinning my mast in rotator clamp (Dave Johnson)
----------------------------------------------------------------------
Message: 1
Date: Wed, 11 Mar 2009 21:57:21 EDT
From: K7LXC at aol.com
Subject: Re: [TowerTalk] Pinning my mast in rotator clamp
To: towertalk at contesting.com, mrlogs at verizon.net
Message-ID: <bc6.3e4fe941.36e9c601 at aol.com>
Content-Type: text/plain; charset="US-ASCII"
In a message dated 3/11/2009 6:45:58 P.M. Pacific Daylight Time,
towertalk-request at contesting.com writes:
> My Yaesu G-1000DXA manual say's to drill thru the mast & put a bolt
thru
the rotator & mast to keep it (the mast) from turning in the clamp. I was
told to do a survey here & get everyone's input on doing this as it might
be a
bad idea..
Well, without being pinned, it would probably move harmlessly out of
alignment. When you pin a mast to a rotator you're transferring the mast
torque
directly to the rotator and the next weak point in the system; usually
gears.
Since Yaesu gave you a long bolt with the rotator and the manual says
to
do it, I'd follow the LXC Prime Directive to "DO what the manufacturer
says."
Cheers,
Steve K7LXC
TOWER TECH
**************Need a job? Find employment help in your area.
(http://yellowpages.aol.com/search?query=employment_agencies&ncid=emlcntusye
lp00000005)
------------------------------
Message: 2
Date: Thu, 12 Mar 2009 02:26:54 -0000
From: "W3YY" <w3yy at cox.net>
Subject: Re: [TowerTalk] Pinning my mast in rotator clamp
To: <TowerTalk at contesting.com>
Message-ID: <9B49D01AF5E94635AFACE9F75B332975 at rtp1>
Content-Type: text/plain; charset="us-ascii"
Tom -
I've always pinned my masts to the rotators, including a G-1000DXA and
G-2800DXA. I've had no problems with the moderate size antennas I use, e.g.
4-el SteppIR, Magnum 240N 2-el 40.
My reasoning was that I didn't want to risk slippage and then have to go up
and realign the antenna. If the rotator broke because it was pinned to the
mast, I felt that just meant I needed a bigger rotator.
The only interesting thing I can add to this discussion is the fact that
bolts used to pin antennas to masts do shear. I thought the force required
to shear even a low grade bolt would be enough to destroy any rotator.
Apparently not so, as I've heard many stories about even high grade bolts
shearing before the rotator failed.
73, Bob - W3YY
-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of mrlogs
Sent: Thursday, March 12, 2009 12:19 AM
To: towertalk at contesting.com
Subject: [TowerTalk] Pinning my mast in rotator clamp
Hi All..
My Yaesu G-1000DXA manual say's to drill thru the mast & put a bolt thru
the rotator & mast to keep it (the mast) from turning in the clamp. I was
told to do a survey here & get everyone's input on doing this as it might be
a bad idea..
Thanks for your input!
73'..Tom N3ZC
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Message: 3
Date: Wed, 11 Mar 2009 20:53:11 -0600
From: "W0MU Mike Fatchett" <w0mu at w0mu.com>
Subject: [TowerTalk] (no subject)
To: "'Tower Talk'" <towertalk at contesting.com>
Message-ID: <33777BAB18E94FF999A5E687FEA0EA19 at hamtower>
Content-Type: text/plain; charset="us-ascii"
I have searched Google for quite a while now and have come up empty.
Has anyone used/modeled/etc an 80m 4 sq over a full sized 4 sq. array?
I have not really found any shortened 80 verticals. I am not sure that a
shortened solution is going save much expense.
I see DX Eng has a 66 ft vertical that needs to be guyed and runs about $200
for the aluminum kit, $160 for the tilt base and about $80 for the guying
kit.
I would be curious to know what others might have used.
I am looking at the bent 4 SQ by K9RS hung off my tower.
I am looking to get a lower angle signal out on 80 for better Dx.
I appreciate the feedback.
Mike W0MU
------------------------------
Message: 4
Date: Wed, 11 Mar 2009 21:30:56 -0600
From: "W0MU Mike Fatchett" <w0mu at w0mu.com>
Subject: [TowerTalk] 80m 4 sq shortened vs full sized
To: "'Billy Cox'" <aa4nu at ix.netcom.com>, "'Tower Talk'"
<towertalk at contesting.com>
Message-ID: <3FF5A28CD7EF4D9A80C8D46704D15C63 at hamtower>
Content-Type: text/plain; charset="us-ascii"
Sorry,
Brain was out thinking the typing fingers LOL! I forgot the subject which
would have helped too.
Yes we are on the same page. Bandwidth is worth considering.
"A slip of the foot you may soon recover, but a slip of the tongue you may
never get over." Ben Franklin
-----Original Message-----
From: Billy Cox [mailto:aa4nu at ix.netcom.com]
Sent: Wednesday, March 11, 2009 9:23 PM
To: W0MU Mike Fatchett
Subject: Re: [TowerTalk] (no subject)
Hey Mike ... are you asking as to a shortened array vs full sized?
<me thinks there is a word missing in your question>
Short answer is ... they will work, AS LONG AS you have a better than
average ground system ... that was my finding when I pondered this very
question before I took my full sized array down for R&R.
The other point mentioned frequently was the bandwidth was better with the
full size ... most ended up using some form of switching to go from CW to
SSB. <Note this was before the SSB band changes>.
So, are we discussing the same thing here?
73/bc/NU
-----Original Message-----
>From: W0MU Mike Fatchett <w0mu at w0mu.com>
>Sent: Mar 11, 2009 10:53 PM
>To: 'Tower Talk' <towertalk at contesting.com>
>Subject: [TowerTalk] (no subject)
>
>I have searched Google for quite a while now and have come up empty.
>
>Has anyone used/modeled/etc an 80m 4 sq over a full sized 4 sq. array?
>
>I have not really found any shortened 80 verticals. I am not sure that
>a shortened solution is going save much expense.
>
>I see DX Eng has a 66 ft vertical that needs to be guyed and runs about
>$200 for the aluminum kit, $160 for the tilt base and about $80 for the
>guying kit.
>
>I would be curious to know what others might have used.
>
>I am looking at the bent 4 SQ by K9RS hung off my tower.
>
>I am looking to get a lower angle signal out on 80 for better Dx.
>
>I appreciate the feedback.
>
>Mike W0MU
>
>
>_______________________________________________
>
>
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk at contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
Message: 5
Date: Thu, 12 Mar 2009 09:42:49 +0100
From: "Kjeld Holm" <kh at kh-translation.dk>
Subject: [TowerTalk] Anchoring of guy wires
To: <towertalk at contesting.com>
Message-ID:
<20090312084246.A84651B5010 at tdcwebmoremail02.tdcwebmore.dk>
Content-Type: text/plain; charset="us-ascii"
Dear all,
Thanks a lot to all who answered my mail in February!
See below what I got from Mark at Force 12 after my reminder to him:
At a wind speed of 120 MPH, the guys and anchor need to be able to take 640
pounds. This number includes the required safety factors. No need to bump
them up any higher - they've been bumped.
Mark
Kjeld Holm wrote:
> Dear Mark
>
> Sorry to bother you again but I desperately need (at least) one number
> regarding the Sigma 80 model H. How much tensile strength does each
> guy wire anchor need to be able to withstand without being pulled out of
the ground?
> You know the H model is using 2 sets of 3 guy wires and is rated at 120
mph.
>
> As much data as possible regarding safe guying of this antenna would
> be appreciated.
>
>
>
> Best regards,
> Kjeld
>
>
------------------------------
Message: 6
Date: Thu, 12 Mar 2009 06:52:16 -0400
From: Pete Smith <n4zr at contesting.com>
Subject: Re: [TowerTalk] Pinning my mast in rotator clamp
To: TOWERTALK at contesting.com
Message-ID: <6.2.0.14.2.20090312064818.08094d50 at mail.comcast.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed
I have two Yaesu rotators, both pinned. The oldest has been up since 1995,
the youngest since 2000. No failures yet, though to be fair, they are both
well within ratings - the G-1000 is turning a Force 12 40m yagi and a Force
12 C-3E tribander, while the G-800 is turning another C-3 on a swinging
gate sidemount. I have had the rotator stall in high winds while turning
the sidemounted yagi, but never seen any damage.
One downside of the pinning method that people may overlook is that you
cannot make fine adjustments of the physical pointing of the antenna at the
mast clamp. On the other hand, it is so easy to adjust the Yaesu direction
indicator that this really isn't much of a problem.
73, Pete
At 08:49 PM 3/11/2009, you wrote:
>It depends on what you choose to break should the turning force on the mast
>exceed the strength of the weakest element. Something has to be the first
>thing to "give". What would you like that to be? What are the
consequences
>of the possible failures you might observe?
>
>In my case, the mast slips in the jaws of the rotator clamp in high winds.
>The rotator clamp hasn't yet shattered or come loose at the rotator. I
have
>a fair amount of mast sticking out above the thrust bearing. If the clamp
>failed completely and ceased to restrain the bottom of the mast, I'd have a
>very strong bending force above the thrust bearing. I would prefer that
the
>clamp slip rather than risk the total failure of the clamp.
>
>Dick, K6KR
>
>
>-----Original Message-----
>From: towertalk-bounces at contesting.com
>[mailto:towertalk-bounces at contesting.com] On Behalf Of mrlogs
>Sent: Wednesday, March 11, 2009 5:19 PM
>To: towertalk at contesting.com
>Subject: [TowerTalk] Pinning my mast in rotator clamp
>
>Hi All..
> My Yaesu G-1000DXA manual say's to drill thru the mast & put a bolt thru
>the rotator & mast to keep it (the mast) from turning in the clamp. I was
>told to do a survey here & get everyone's input on doing this as it might
be
>a bad idea..
> Thanks for your input!
> 73'..Tom N3ZC
>_______________________________________________
>
>
>
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------------------------------
Message: 7
Date: Thu, 12 Mar 2009 07:04:07 -0400
From: Pete Smith <n4zr at contesting.com>
Subject: Re: [TowerTalk] Pinning my mast in rotator clamp
To: towertalk at contesting.com,mrlogs at verizon.net
Message-ID: <6.2.0.14.2.20090312065948.09307e10 at mail.comcast.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed
It is also VERY important to follow Yaesu's instructions for the tightening
sequence of the mast clamps. Properly done, it winds up tight and
well-centered on the rotator. Improperly done, it can break the clamps as
the bolts try to bend the cast clamps to fit the mast. If you tighten the
clamps to the mast first, then center and tighten the bolts attaching the
clamp to the rotator body, and LAST tighten the bolts holding the rotator
to the shelf, you should have no trouble. If you can't get the clamp
centered on the top of the rotator, there's something wrong with either the
mast or the rotator shelf, and you'll pay if you don't fix that first.
73, Pete N4ZR
At 09:57 PM 3/11/2009, K7LXC at aol.com wrote:
>
>In a message dated 3/11/2009 6:45:58 P.M. Pacific Daylight Time,
>towertalk-request at contesting.com writes:
>
> > My Yaesu G-1000DXA manual say's to drill thru the mast & put a bolt
> thru
>the rotator & mast to keep it (the mast) from turning in the clamp. I was
>told to do a survey here & get everyone's input on doing this as it might
>be a
>bad idea..
>
>
> Well, without being pinned, it would probably move harmlessly out of
>alignment. When you pin a mast to a rotator you're transferring the mast
>torque
>directly to the rotator and the next weak point in the system; usually
>gears.
>
> Since Yaesu gave you a long bolt with the rotator and the manual
> says to
>do it, I'd follow the LXC Prime Directive to "DO what the manufacturer
says."
>
>Cheers,
>Steve K7LXC
>TOWER TECH
>
>
>
>
>
>**************Need a job? Find employment help in your area.
>(http://yellowpages.aol.com/search?query=employment_agencies&ncid=emlcntusy
elp00000005)
>_______________________________________________
>
>
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk at contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
------------------------------
Message: 8
Date: Wed, 11 Mar 2009 09:09:04 -0400
From: "Chris Davis" <Chris.Davis at spmachine.com>
Subject: [TowerTalk] need some help with 4130 material....
To: <towertalk at contesting.com>
Message-ID: <003001c9a24a$8e673d60$ab35b820$@Davis at spmachine.com>
Content-Type: text/plain; charset="us-ascii"
I have a vendor that is requesting a product to be made from 4130 A519. My
question to you is, is there a difference between 4130 ASTM 519 and 4130 AMS
6360? Any help you can give on this matter would be greatly appreciated.
------------------------------
Message: 9
Date: Wed, 11 Mar 2009 16:53:48 -0700
From: "J. Wolfe" <JWolfe at ProgressiveSystemsInc.org>
Subject: [TowerTalk] Parts fo A HAM II
To: "Tower Talk" <towertalk at contesting.com>
Message-ID: <017501c9a2a4$9ff9e320$cd01a8c0 at main>
Content-Type: text/plain; charset="iso-8859-1"
I have an older rotator...a CDE HAM II..need the lower housing (Brake cogs
are toast) and the brake assembly itself.
Any suggestions?
Thanks in advance
Joe Wolfe
WA6RKN
------------------------------
Message: 10
Date: Wed, 11 Mar 2009 22:40:34 -0400
From: "Dave Johnson" <djohnson at windstream.net>
Subject: Re: [TowerTalk] Pinning my mast in rotator clamp
To: "mrlogs" <mrlogs at verizon.net>, <towertalk at contesting.com>
Message-ID: <8B2B1DFA75B648F18E0421E860CBAA2A at Vision>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I would say that it depends on how much wind load you will have attached to
the rotor mast or how long your antenna boom is. If you have one antenna
with a boom of 30' or less you would likely never have a problem. However,
with long boom antennas, it is a pain in the you know where when you must
climb the tower and move the antenna back where it was after a strong wind.
I had a friend that had a KLM 20 meter Big Stick with a 60' long boom. He
had a bolt through the rotor and mast but that antenna kept shearing off the
bolt. It never damaged the rotor. When he moved, I took his antenna and
tower down. When I took the mast out of the rotor, a hand full of broken
bolts came out of the mast.
If you decide to drill the mast, put it in the rotor and drill one side then
move the drill to the other side and drill again. Don't try to drill all
the way through both halves of the mast from the same side.
73, Dave - K4SSU
----- Original Message -----
From: "mrlogs" <mrlogs at verizon.net>
To: <towertalk at contesting.com>
Sent: Wednesday, March 11, 2009 8:19 PM
Subject: [TowerTalk] Pinning my mast in rotator clamp
> Hi All..
> My Yaesu G-1000DXA manual say's to drill thru the mast & put a bolt thru
> the rotator & mast to keep it (the mast) from turning in the clamp. I was
> told to do a survey here & get everyone's input on doing this as it might
> be a bad idea..
> Thanks for your input!
> 73'..Tom N3ZC
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
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