[TowerTalk] Sources for SS Hardware ??
n0tt1 at juno.com
n0tt1 at juno.com
Thu Nov 10 17:53:42 EST 2022
I use McMaster.com and the local Menards (big box) store
for less critical projects. I like Menard's larger yet very affordable
packs of say, SS bolts,
instead of other stores that might have say, only two bolts in a bubble
pack for sky-high
prices.
Charlie, N0TT
On Thu, 10 Nov 2022 17:22:43 +0000 Steve Davis | Davis RF
<sdavis at davisrf.com> writes:
> Hello T-Talkers !
>
> Wondering what your recommended sources for SS hardware
> nowadays??
>
> If you recommend a source, could you say yes or no as to knowing if
> made in China or not??
>
> For those businesses recommended, but unknown if mfd. In China, I
> will find out and recap to you.
>
> In my biz we stay away from anything MIC, unless , for instance, it
> is a Times Microwave product where they have a US citizen handling
> QC at the Chinese factory they lease.
>
> I have attached a link to a fairly good synopsis of the various
> types, and grades of SS
>
> https://www.unifiedalloys.com/blog/stainless-grades-families
>
> Tnx, 73, good DX, Steve Davis, K1PEK
> DAVIS RF Co.
> DAVIS ROPE AND CABLE, LLC (metallic cable)
>
>
> From: TowerTalk <towertalk-bounces at contesting.com> on behalf of
> towertalk-request at contesting.com <towertalk-request at contesting.com>
> Date: Thursday, November 10, 2022 at 12:01 PM
> To: towertalk at contesting.com <towertalk at contesting.com>
> Subject: TowerTalk Digest, Vol 239, Issue 9
> Send TowerTalk mailing list submissions to
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> Today's Topics:
>
> 1. Re: Antenna ID help (jcjacobsen)
> 2. Re: More friction needed (JVarney)
> 3. Re: Antenna ID help (Jim W7RY)
> 4. Mast clamp friction (k7lxc at aol.com)
> 5. Tnx for all the mast friction comments! (k7lxc at aol.com)
> 6. m2 rotator slippage (STEPHEN L SALA)
> 7. Re: Antenna ID help (Floyd Rodgers)
> 8. Re: More friction needed (Grant Saviers)
> 9. Re: More friction needed (JVarney)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 09 Nov 2022 09:52:47 -0800
> From: jcjacobsen <jcjacobsen at q.com>
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Antenna ID help
> Message-ID: <96WVN5WTCIU4.EKDC04CPXB2C at luweb02oc>
> Content-Type: text/plain; charset=utf-8
>
> Hello Towertalkians
>
>
> Need help ID'ing a 2 meter yagi. Haven't been able to find anything
> on line, probably because of its age. I thought maybe a Hy-Gain or
> KLM, but no joy.
> So I'm turning to the collective memory of the old timers on the
> reflector.
>
>
> 11 elements. Aprox 14' boom. Has a 4 element LogCell for a driven
> element.
>
>
> Any help out there??
>
>
> Thanks in advance.
>
>
> 73 K9WN Jake
>
> ------------------------------
>
> Message: 2
> Date: Wed, 9 Nov 2022 10:25:55 -0800
> From: JVarney <jvarn359 at gmail.com>
> To: "[TowerTalk]" <towertalk at contesting.com>
> Subject: Re: [TowerTalk] More friction needed
> Message-ID:
>
> <CANx7Etau459BoSsaEcLqxkcnByCeCwgSc_S5bbkyCG=5RFgOVQ at mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
>
> Dave AB7E wrote>> Personally, I think the idea of using multiple
> U-bolts is
> the best way to go. <<
>
> I agree. And instead of shooting from the hip and guessing, with
> U-bolts
> you can calculate and
> engineer the number and size of U-bolts needed to resist the mast
> torque.
> This is a simplified
> version of the procedure in TIA-222-H
>
> Nominal torsional strength of U-bolt assembly = Tr = 0.075 (D)(Tp)
> Tp = assumed U-bolt leg tension = (20 ksi)(Ag of leg)
>
> where D = mast diameter, Ag = gross area of U-bolt leg. English
> units.
>
> U-bolts should not be tightened past yield and should be limited to
> 0.85 Fy
> Ag.
>
> ===
>
> Example: 3 3/8 U-bolts and a 2-in mast.
>
> Ag leg = 0.19 sq in
> Tp = 20 ksi x 0.19 = 3800 lbs
> Tr = 0.075 ( 2 in )(3800) = 570 in-lbs per leg
>
> System Tr = (3 U-bolts)(2 legs each)(570 in-lbs) = 3,420 in-lbs
> torque
> resistance
>
> ===
>
> Considering a Yaesu G-800 has a brake resistance 0f 4,000 in-lbs,
> the 3
> U-bolts is
> in the ballpark for a medium tribander. If you ignore the 20k yield
> assumption and use
> 42k yield for stainless and tighten to 0.85FyAg, that gets you 1,000
> in-lbs
> per leg,
> equal to 6,000 in-lbs total torque resistance.
>
> This simplified estimate ignores vertical slippage forces due to the
> weight
> of the
> mast and antenna acting on the U-bolts, which reduces the available
> torque
> resistance somewhat.
>
> 73 Jim K6OK
>
>
> ------------------------------
>
> Message: 3
> Date: Wed, 9 Nov 2022 12:26:38 -0600
> From: Jim W7RY <jimw7ry at gmail.com>
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Antenna ID help
> Message-ID: <8adc514b-7877-edd4-5fd9-dd943c608c5f at gmail.com>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> If you post this on towertalk on the groups.io list, you could
> attache a
> picture.
>
> Feel free to join.
> 73, Jim W7RY
>
>
> On 11/9/2022 11:52 AM, jcjacobsen via TowerTalk wrote:
> > Hello Towertalkians
> >
> >
> > Need help ID'ing a 2 meter yagi. Haven't been able to find
> anything on line, probably because of its age. I thought maybe a
> Hy-Gain or KLM, but no joy.
> > So I'm turning to the collective memory of the old timers on the
> reflector.
> >
> >
> > 11 elements. Aprox 14' boom. Has a 4 element LogCell for a driven
> element.
> >
> >
> > Any help out there??
> >
> >
> > Thanks in advance.
> >
> >
> > 73 K9WN Jake
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk at contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
>
> --
> Thanks and 73, Jim W7RY
>
>
> ------------------------------
>
> Message: 4
> Date: Wed, 9 Nov 2022 18:38:05 +0000 (UTC)
> From: <k7lxc at aol.com>
> To: towertalk at contesting.com
> Subject: [TowerTalk] Mast clamp friction
> Message-ID: <908629317.427392.1668019085374 at mail.yahoo.com>
> Content-Type: text/plain; charset=UTF-8
>
> ? ? Here is a cheap and elegant way to increase the friction.?
> ?Cheers,Steve? ? ?K7LXC? If I need for a clamp to hold without
> slipping, this is what I do.? I am
> a retired machinist.
>
> I make my own 3 inch saddles from 3/4 x 1 1/2 billet aluminum.
>
> I use hot dipped galvanized U-bolts, as SS bolts all seem to be
> 'one
> time' use, before failure.
>
> I use a light duty adhesive sprayed on the 'bore' part of the
> saddle.?
> Women's hair spray works fine.
>
> While wet, sprinkle silicon carbide particles on the adhesive. This
> size
> is about like ground pepper from a pepper mill.
>
> Assemble and tighten down.? The silicon carbide presses into both
> the
> aluminum saddles and into the zinc on the galvanized mast. It will
> not
> slip!?? Be careful in handling the mast/saddles; the silicon carbide
> can
> be hard on the hands.
>
> 73 de Steve, NR4M
>
> ------------------------------
>
> Message: 5
> Date: Wed, 9 Nov 2022 18:39:48 +0000 (UTC)
> From: <k7lxc at aol.com>
> To: towertalk at contesting.com
> Subject: [TowerTalk] Tnx for all the mast friction comments!
> Message-ID: <1957544183.426550.1668019188891 at mail.yahoo.com>
> Content-Type: text/plain; charset=UTF-8
>
> Cheers,
> Steve? ? ?K7LXC
>
> ------------------------------
>
> Message: 6
> Date: Wed, 9 Nov 2022 18:44:25 +0000
> From: STEPHEN L SALA <k7awb at msn.com>
> To: "towertalk at contesting.com" <towertalk at contesting.com>
> Subject: [TowerTalk] m2 rotator slippage
> Message-ID:
>
>
<CH3PR14MB620281C362505B3ACCC14011ED3E9 at CH3PR14MB6202.namprd14.prod.outlo
ok.com>
>
> Content-Type: text/plain; charset="utf-8"
>
> steve k7lxc:
> several years ago i had that same problem and your company sold me a
> large metal two-piece bracket as a replacement for the M2 parts
> (yours had holes for 6 clamps.
>
> it worked perfectly and it has been about ten years up there. don?t
> you have one in storage to use yourself?
>
> Stephen
> K7awb
> DN17es
>
> ------------------------------
>
> Message: 7
> Date: Wed, 9 Nov 2022 19:01:02 +0000 (UTC)
> From: Floyd Rodgers <kc5qbc at swbell.net>
> To: "towertalk at contesting.com" <towertalk at contesting.com>,
> jcjacobsen
> <jcjacobsen at q.com>
> Subject: Re: [TowerTalk] Antenna ID help
> Message-ID: <84951341.439002.1668020462813 at mail.yahoo.com>
> Content-Type: text/plain; charset=UTF-8
>
> Most likely a klm of 70's? vintage.?
> On Wednesday, November 9, 2022 at 11:52:59 AM CST, jcjacobsen
> via TowerTalk <towertalk at contesting.com> wrote:
>
> Hello Towertalkians
>
>
> Need help ID'ing a 2 meter yagi. Haven't been able to find anything
> on line, probably because of its age. I thought maybe a Hy-Gain or
> KLM, but no joy.
> So I'm turning to the collective memory of the old timers on the
> reflector.
>
>
> 11 elements. Aprox 14' boom. Has a 4 element LogCell for a driven
> element.
>
>
> Any help out there??
>
>
> Thanks in advance.
>
>
> 73 K9WN? Jake
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
> ------------------------------
>
> Message: 8
> Date: Wed, 9 Nov 2022 13:49:47 -0800
> From: Grant Saviers <grants2 at pacbell.net>
> To: Steve Dyer W1SRD <w1srd at yahoo.com>,
> "'towertalk at contesting.com'"
> <towertalk at contesting.com>
> Subject: Re: [TowerTalk] More friction needed
> Message-ID: <f80b1c5e-3ead-e707-4474-dccc1df693f2 at pacbell.net>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> The work can be done on many home shop lathes - 12x36 and even some
> smaller, so check around for who might be willing to help.
>
> A piece of tubing or a mandrel of most anything the size of the
> mast
> minus 0.050" or so makes the setup easier - centering the two halves
> and
> then boring to the desired diameter, recenter and repeat as
> necessary to
> get a square bore and enough teeth and area on the teeth. Three or
> 4
> cleaned up teeth per row on each half with 1/4" contact areas is
> what I
> decided was about right. While I bored for a 3" mast, I think the
> casting should work for a 2" bore.
>
> An hour or two of lathe time if you can find a commercial shop
> willing
> to take it on.
>
> It's clear the design intent was to work with all mast diameters,
> but
> that limits the possible tooth engagement. Then adding casting
> variability created a marginal clamp system. Mold wear yields more
> variability and base machining is difficult to get square on the
> cast
> teeth. It's a classic problem in machining an iron casting - what
> is
> the best reference surface or where should one be machined?
>
> I think many masts slip because bolts are not tightened to spec and
> not
> retightened evenly another couple of times. Also, using stainless
> steel
> bolts, some of which have a tendency to stretch a bit over time.
> My
> DB36 stock mast clamp slipped 3 times before I reinforced the
> aluminum
> "C" clamps on the backside with 1/2" thick steel bar and used grade
> 8
> bolts torqued to spec 3x. The stock "C" collar pair would close to
> tips
> touching and that made further tightening useless.
>
> I am also a big fan of the DX Engineering cast saddle U bolt clamp
> sets.
> The saddle has a large contact area with the mast or tube and my
> choice for all home brew antennas. Never had one slip. A great
> part
> for making a multi U bolt mast clamp.
>
> A u-bolt holding a tube against a flat plate may have only 2
> contact
> points. Using many u-bolts is one approach. Deforming the u-bolts
> to
> increase the "wrap" is another. Or flattening the tube.
>
> Grant KZ1W
>
> On 11/8/2022 17:42, Steve Dyer W1SRD via TowerTalk wrote:
> > What would a competent machine shop charge to do this? Most of us
> don't
> > have a fully outfitted machine shop :-).
> > 73,
> > Steve
> > W1SRD
> >> Bolt the two clamp sections to a lathe faceplate and bore them to
> the
> >> mast diameter.? Remove enough material to enlarge the contact area
> and
> >> insure the bore is true to the bases.? Use grade 8 bolts and use
> a
> >> torque wrench to max spec torque for the size bolt.? Repeat this
> >> tightening 3 times.
> >>
> >> The clamp bore as cast wasn't straight to the machined base and
> only a
> >> few "points" would have made contact in the 2800 I have turning a
> 375#
> >> 100ft tip to tip 2L 80m beam.? Now it doesn't slip.
> >>
> >> Grant KZ1W
> >>
> >> On 11/8/2022 10:00, k7lxc--- via TowerTalk wrote:
> >>> Howdy, TowerTalkians -
> >>> ??? ? I need more friction between an M2 mast clamp and the
> mast. How
> >>> could I do that? What materials would work? Tnx.?Cheers,Steve
> >>> K7LXCCell: 206-890-4188
> >>> _______________________________________________
> >>>
> >>>
> >>>
> >>> _______________________________________________
> >>> TowerTalk mailing list
> >>> TowerTalk at contesting.com
> >>> http://lists.contesting.com/mailman/listinfo/towertalk
> >> _______________________________________________
> >>
> >>
> >>
> >> _______________________________________________
> >> TowerTalk mailing list
> >> TowerTalk at contesting.com
> >> http://lists.contesting.com/mailman/listinfo/towertalk
> >
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk at contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
>
>
> ------------------------------
>
> Message: 9
> Date: Wed, 9 Nov 2022 16:02:12 -0800
> From: JVarney <jvarn359 at gmail.com>
> To: "[TowerTalk]" <towertalk at contesting.com>
> Subject: Re: [TowerTalk] More friction needed
> Message-ID:
>
> <CANx7EtaoOBaqqhECc_sz6Wts-i0wyYP1XVKERCShxa2unw5xEg at mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
>
> Sorry my Gmail messed up the line breaks and made it
> unreadable. Reposting for anyone interested in calculating
> U-bolt torsion resistance for masts.
>
> I'm fairly confident this method is a good approximation
> because the TIA committee, composed of experienced engineers
> in the tower industry, wouldn't write this into the
> building code unless it had good support.
>
>
> ----------------------------------------------------------------
> Dave AB7E wrote>> Personally, I think the idea of using multiple
> U-bolts is the best way to go. <<
>
> I agree. And instead of shooting from the hip and guessing,
> with U-bolts you can calculate and engineer the number and size
> of U-bolts needed to resist the mast torque. This is a simplified
> version of the procedure in TIA-222-H
>
> Nominal torsional strength of U-bolt assembly = Tr
> Tr = 0.075 (D)(Tp)
> Tp = assumed U-bolt leg tension = (20 ksi)(Ag of leg)
> where D = mast diameter, Ag = gross area of U-bolt leg.
>
> U-bolts should not be tightened past yield and should be limited
> to 0.85 Fy Ag.
>
> ===
>
> Example: 3 3/8 U-bolts and a 2-in mast.
>
> Ag leg = 0.19 sq in Tp = 20 ksi x 0.19 = 3800 lbs
> Tr = 0.075 ( 2 in )(3800) = 570 in-lbs per leg
> System Tr = (3 U-bolts)(2 legs each)(570 in-lbs) = 3,420 in-lbs
> torque resistance
>
> ===
>
> Considering a Yaesu G-800 has a brake resistance 0f 4,000 in-lbs,
> the 3 U-bolts is in the ballpark for a medium tribander.
> If you ignore the 20k yield assumption and use 42k yield
> for stainless and tighten to 0.85FyAg, that gets you 1,000
> in-lbs per leg, equal to 6,000 in-lbs total torque resistance.
>
> This simplified estimate ignores vertical slippage forces due
> to the weight of the mast and antenna acting on the U-bolts,
> which reduces the available torque resistance somewhat.
>
> 73 Jim K6OK
>
>
> ------------------------------
>
> Subject: Digest Footer
>
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> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
> ------------------------------
>
> End of TowerTalk Digest, Vol 239, Issue 9
> *****************************************
> _______________________________________________
>
>
>
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