[TowerTalk] Chrome Moly Mast pipe
trappaport at austin.rr.com
trappaport at austin.rr.com
Mon Oct 12 00:49:25 PDT 2009
Several of you asked why I am using 3" solid steel mast pipe, and what I am putting on top of it. I have gained a great education the past few months, learning about tower design, and the new TIA 222G regulations. These new regulations will likely impact all of us in the ham community eventually, especially if we live on mountain tops or are at least half way up a ridge. I had purchased the Chrome Moly mast pipes thinking, like many of you, that this would be extremely rugged and sufficient for my setup. And it is, indeed, suitable for most installations. However, as I have learned, it turns out that the TIA 222G tower guidelines have a special wind acceleration factor for mountain top locations, causing the wind speed calculations to actually increase by X2 or X3 up the mountain from what 222F currently assumes.
It might be fair to argue that no one really knows if 222G makes sense -- it may be EXTREME Overkill for mountain top locations -- perhaps requiring far beyond a reasonable amount of overdesign -- but we don't really know, and my guess is that counties across America are going to insist on the new rules, and I suspect that this will require law abiding hams to beef up any new installations to meet these building permit rules.
In my case, I am at the top of a ridge, at 2550' ft. above sea level in Montgomery County, VA - we are building this as our summer retreat and contest station ( I live and work in TX, but our family likes to spend summers in SW Virginia and work often takes me to the Virginia/DC area).
I graded the top of the ridge to make a 2 acre flat "postage stamp" area for towers, antennas, wires, experimentation, and a general antenna farm playground. Since I have never owned a tower before, and never before had any land to use for antennas, I want to do things right, a sort of "once in a lifetime" installation, and am willing to pay the extra money up front in hopes of years of hassle free, worry free operations. I even have an abandonded water well in the middle of the postage stamp, serving as a 300' ground rod.
My goal is to build a very rugged station that will survive 120 MPH winds under TIA 222 G (As mentioned, the 222G guidelines provide very rigid standards as compared to the venerable 222F). Even though the county only required 80mph in its building code, I wanted to beef up the requirement to account for a "black swan" wind event like the region experienced when Hurricane Andrew came through the Blacksburg, VA and uprooted gian trees in the early 1990s. Furthermore, I also want the antenna and tower to withstand 60 MPH with 3/4" ice, as it can get really nasty and windy on the mountain top. The county only requires 30 MPH with 3/4" ice using 222G in its building code for towers, but I wanted to double this rating, as I anticipate alot of concurrent ice and wind at this particular location, and want this to be a "bullet proof" installation. The design also contemplates the addition of lower yagis for 10- 40 m closer to ground level.
Mark Hooper at Force 12 built for me Heavy Duty 120 MPH rated ruggedized versions of antennas for special use on the mountain top, with boom and element trusses both above and below the elements (to handle updraft from the ground). I am initially putting up 2 identical towers, spaced 130' apart.
My zoning regulations require 75' max. tower height, so to get enough seperation between the tribander (c31xr) and 40m yagi (240N) on a single mast, I will put up 65' guyed towers and have 10' of mast protruding above the tower. PE calculations by several different tower companies verified that the Mast Pipe was the weakest link if I use a solid steel tower. Rohn told me I needed a 5" OD mast pipe (!), other tower companies suggested between 3" to 7" mast pipes (!), all based on the 222G requirements and my self-imposed ice requirement. After many months of due dilligence, I am putting up solid steel 18" towers from World Tower -- a crane will be used to set this up. World Tower makes cellphone towers, and they are putting in custom full width climbing steps on 2 faces of the tower, and the hardline will come down the 3rd face of the tower. They have been terrific to work with. The PE there is Kirk Hall, and he is really a knowledgeable and terrific engineer, and the tower company has been very easy to work with (not all tower companies are). Kirk ran many calculations, and found that a 3" solid steel pipe would meet my requirements, while working with standard rotors like the Orion M2.
Unfortunately, I found this out after I bought the ChromeMoly mast pipe (!), thus I am selling the 4 mast pipes at my cost (and a slight discount if someone buys all 4).
Its been quite an education, learning about 222G and its impact on the tower design. If I wanted to meet the county's 30 mph 3/4" guideline and 80 mph wind, the ChromeMoly would have been fine, but I wanted to "amp up the design" to avoid the hassle factor down the road. I hope the extra investment is worth it. If nothing else, I will sleep better at night if there is an ice storm on the mountain while I am in Texas.
73
ted n9nb
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> Today's Topics:
>
> 1. Re: US Tower install - help request (Mat Eshpeter)
> 2. Chrome Moly Mast Pipes for sale (trappaport at austin.rr.com)
> 3. Re: Rusty washers on one-piece SO239 connectors (Roger (K8RI))
> 4. Re: Chrome Moly Mast Pipes for sale (Pete Stark K4OM)
> 5. Re: Chrome Moly Mast Pipes for sale (john at kk9a.com)
> 6. Re: Orion Rotor Indication Trouble (john at kk9a.com)
> 7. Re: Chrome Moly Mast Pipes for sale (john at kk9a.com)
> 8. Re: US Tower install - help request (Rick Karlquist)
> 9. Half-Square Guidance (Michael Dinkelman)
> 10. Re: Need: Hy Gain TH6DX Manual (PDF) (Jim Hargrave)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sat, 10 Oct 2009 19:12:18 -0400
> From: Mat Eshpeter <kk1c at live.com>
> Subject: Re: [TowerTalk] US Tower install - help request
> To: <towertalk at contesting.com>
> Message-ID: <SNT123-W33EA9D7AD6A0F810ED0ECF1CA0 at phx.gbl>
> Content-Type: text/plain; charset="Windows-1252"
>
>
> Thanks for the tremendous responses. I will begin calling some of you shortly.
>
> For those that I don't end up calling, thanks for the offer.
>
> 73,
> mat
> kk1c
>
> > Date: Sat, 10 Oct 2009 18:41:16 -0400
> > From: randy at gte.net
> > CC: towertalk at contesting.com
> > Subject: Re: [TowerTalk] US Tower install - help request
> >
> > AFAIK, it is *crucial* to do it as specified with regard to "undisturbed
> > soil". In other words, they do not want you to dig a hole,
> > form it up, backfill behind it and pour. They want a plain ol' hole in
> > the dirt, with the concrete/rebar in it. And, that may be where
> > the biggest danger lies, digging an 8' deep hole, straight down. I was
> > lucky, and was able to do it with a Terra Mite mini-backhoe.
> > Barely deep enough, though. Obviously, you'd need some form of form to
> > protect you if you were hand digging it.
> > Mike, K4CVL had his hand-dug and may be able to offer advice on the
> > temporary "forms" for protection.
> > My only comments on the rebar: the drawing seems to show one fewer
> > "hoop" than is indicated in the tables....?
> > And, I "X"'ed all 4 sides with pieces 4' pieces of rebar from Home Depot
> > for rigidity while handling...
> > I'd gladly talk to you on the phone, if I had any more advice than that
> > to offer.
> > Good luck with the project.
> >
> > 73,
> > Randy
> > KZ4RV
> >
> > Mat Eshpeter wrote:
> > > I am about to install a US Tower crankup model HDX589. I would like to talk (via phone) to anyone who has installed a US Tower crankup and can help me with some general questions related to the concrete base work -- rebar work, Ufer ground, conduit, general questions about how to set the base up properly, any caveats that I should be aware of.
> > >
> > > Please send me your contact info and a good time to call this weekend.
> > >
> > > I do not have an installation manual -- if anyone has a PDF of the installation manual, I would be grateful to get a copy. At the moment I am planning on digging a hole with dimensions 5' 6" x 5' 6" x 9' 0" deep; I got these measurements from the US Tower web site and I hope they are correct.
> > >
> > > Also, at the risk of appearing too greedy, I would be grateful for onsite assistance from any experts willing to travel to the future station location near Romney, WV. Please contact me off-list.
> > >
> > > Thanks,
> > > Mat
> > >
> > > _________________________________________________________________
> > > Your E-mail and More On-the-Go. Get Windows Live Hotmail Free.
> > > http://clk.atdmt.com/GBL/go/171222985/direct/01/
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> ------------------------------
>
> Message: 2
> Date: Sat, 10 Oct 2009 23:15:00 +0000
> From: <trappaport at austin.rr.com>
> Subject: [TowerTalk] Chrome Moly Mast Pipes for sale
> To: towertalk at contesting.com
> Message-ID: <20091010231500.DHAEE.545325.root at hrndva-web01-z01>
> Content-Type: text/plain; charset=utf-8
>
> I have 4 mast pipes, each about 17' long, made of Chrome Moly steel, which I bought recently but cannot use (I am going with a 3" solid steel stick). I will sell each of these masts for $250 each, or $900 for the lot of 4. I have original specification sheet with engineering data, about 108 KSI each.
>
> Two of the mast pipes are 2" O.D. with 1/2" wall thickness.
> Two of the mast pipes are 2.5" O.D. with 3/16" wall thickness.
>
> Please send an email if you have a need and are interested. I prefer pick up from Riner, VA but can ship if you arrange and pay for shipping.
>
> Ted N9NB trappaport at austin.rr.com
>
>
> ------------------------------
>
> Message: 3
> Date: Sat, 10 Oct 2009 19:27:30 -0400
> From: "Roger (K8RI)" <K8RI-on-TowerTalk at tm.net>
> Subject: Re: [TowerTalk] Rusty washers on one-piece SO239 connectors
> To: Patrick Barkey <n9rvee at gmail.com>
> Cc: towertalk at contesting.com
> Message-ID: <4AD11862.1070106 at tm.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>
>
> Patrick Barkey wrote:
> > I am refurbishing a switch that was outdoors for a while that uses the SO239
> > connectors that have a locking nut on the connector body instead of the four
> > little screws to mount it to the chassis.
> >
> > A picture can be found here: http://drawings.amphenolrf.com/pdf/189.pdf
> >
> > Under the caption "83-878."
> >
>
> That is a "rear mount" and for outdoor use I'd think you'd want the
> "front mount" or 83-875. That puts the washer on the inside and out of
> the weather so when the connector is weatherproofed the washer is protected.
> However that doesn't answer the question for a thinner washer and I
> don't have an answer for that.
>
> 73
>
> Roger (K8RI)
> > The problem is that the internal tooth lockwasher is zinc plated and has
> > rusted. I went to a local connector place and got some replacements that
> > were stainless, but they were thicker and wider and don't allow enough
> > thread for a PL-259 to tighten properly.
> >
> > Does anyone know of a source for a stainless versions of the small zinc
> > washers that come with these connectors? Thanks.
> >
> > - Pat
> > N9RV
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk at contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
> >
>
>
> ------------------------------
>
> Message: 4
> Date: Sat, 10 Oct 2009 19:38:41 -0400
> From: "Pete Stark K4OM" <pstark at suddenlink.net>
> Subject: Re: [TowerTalk] Chrome Moly Mast Pipes for sale
> To: <trappaport at austin.rr.com>, <towertalk at contesting.com>
> Message-ID: <349FF3E032B64AC38444886B1EF8907C at PeteLRPC>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
>
> What does a 3" solid rod weigh per foot?
> And what do you plan to hang on it?
>
> Pete K4OM
>
>
>
> ----- Original Message -----
> From: <trappaport at austin.rr.com>
> To: <towertalk at contesting.com>
> Sent: Saturday, October 10, 2009 7:15 PM
> Subject: [TowerTalk] Chrome Moly Mast Pipes for sale
>
>
> >I have 4 mast pipes, each about 17' long, made of Chrome Moly steel, which
> >I bought recently but cannot use (I am going with a 3" solid steel stick).
> >I will sell each of these masts for $250 each, or $900 for the lot of 4. I
> >have original specification sheet with engineering data, about 108 KSI
> >each.
> >
> > Two of the mast pipes are 2" O.D. with 1/2" wall thickness.
> > Two of the mast pipes are 2.5" O.D. with 3/16" wall thickness.
> >
> > Please send an email if you have a need and are interested. I prefer pick
> > up from Riner, VA but can ship if you arrange and pay for shipping.
> >
> > Ted N9NB trappaport at austin.rr.com
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk at contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
>
>
> ------------------------------
>
> Message: 5
> Date: Sat, 10 Oct 2009 20:59:51 -0400
> From: <john at kk9a.com>
> Subject: Re: [TowerTalk] Chrome Moly Mast Pipes for sale
> To: <TOWERTALK at contesting.com>
> Cc: pstark at suddenlink.net
> Message-ID: <667276D0A67C4AF388F11B9007B313CB at Office>
> Content-Type: text/plain; charset="iso-8859-1"
>
> The weight of steel is approximately 0.283 pounds / sq inch. So 12" of 3"
> round weighs: pi * 1.5(sq) * 12 * .283 = 24 pounds
>
> John KK9A
>
>
>
> To: <towertalk at contesting.com>
> Subject: Re: [TowerTalk] Chrome Moly Mast Pipes for sale
> From: "Pete Stark K4OM" <
> Date: Sat, 10 Oct 2009 19:38:41 -0400
> List-post: <towertalk at contesting.com">mailto:towertalk at contesting.com>
>
> What does a 3" solid rod weigh per foot?
> And what do you plan to hang on it?
>
> Pete K4OM
>
>
>
> ------------------------------
>
> Message: 6
> Date: Sat, 10 Oct 2009 21:05:02 -0400
> From: <john at kk9a.com>
> Subject: Re: [TowerTalk] Orion Rotor Indication Trouble
> To: <TOWERTALK at contesting.com>
> Message-ID: <D817EE5C80414AFA93EA6E773A4914FD at Office>
> Content-Type: text/plain; charset="iso-8859-1"
>
> I'm not sure how long your cable is, but this may not work for longer runs.
>
> John KK9A
>
>
>
>
> To: "'TOWERTALK'" <towertalk at contesting.com>
> Subject: Re: [TowerTalk] Orion Rotor Indication Trouble
> From: "wa5zup" <wa5zup at msn.com>
> Date: Sat, 10 Oct 2009 08:03:27 -0600
> List-post: <towertalk at contesting.com">mailto:towertalk at contesting.com>
>
> I agree on the urban legend.
> I used a single cable on mine. 2c/#12 and 2c/#18 shielded in one cable. It
> is the same as the pigtail that comes out of the rotor (recent). The
> Wireman sells it. It has worked with no issues.
> 73 John wa5zup
>
>
> -----Original Message-----
> From: towertalk-bounces at contesting.com
> [mailto:towertalk-bounces at contesting.com] On Behalf Of
> donovanf at starpower.net
> Sent: Saturday, October 10, 2009 6:49 AM
> To: 'TOWERTALK'
> Subject: Re: [TowerTalk] Orion Rotor Indication Trouble
>
> Yes, it likely that the reed switch is sticking intermittently.
>
> Its an urban legend that RG-59 is needed on the sensor lines. All thats
> needed is separate cables for the motor lines and the sensor lines. The
> inaccurate indicator problem arises when all four wires are bundled in the
> same cable.
>
> 73
> Frank
> W3LPL
>
>
>
> ---- Original message ----
> >Date: Sat, 10 Oct 2009 06:30:10 -0600
> >From: "wa5zup" <wa5zup at msn.com>
> >Subject: Re: [TowerTalk] Orion Rotor Indication Trouble
> >To: "'TOWERTALK'" <towertalk at contesting.com>
> >
> >I suspect that you have a bad reed switch in the rotor.
> >M2 sells them for $25.
> >I am pretty sure you can not replace it on the tower, I might be wrong.
> >Getting the rotor out and down to replace it will be the hard part.
> >If you do that, I suggest testing it completely on the ground, before
> >putting it back up.
> >73 John wa5zup
> >
> >-----Original Message-----
> >From: towertalk-bounces at contesting.com
> >[mailto:towertalk-bounces at contesting.com] On Behalf Of Jim Harvey
> >Sent: Friday, October 09, 2009 9:27 PM
> >To: 'TOWERTALK'
> >Subject: [TowerTalk] Orion Rotor Indication Trouble
> >
> >After a tower rebuild this summer my Orion rotor began giving me
> >intermittent direction indication readings. The unit will quit turning
> >normally and will only turn in very small increments and not indicate
> >direction correctly. When it does come back to life the controller must be
> >reprogrammed and then it will be fine for awhile only to start the cycle
> >over again. M2 recommended using shielded cable for the sensor lines so I
> >used some RG59 for each lead and thought that the problem had been fixed.
> >Unfortunately this past week the trouble has appeared again. In addition to
> >the change to shielded cable I have also tried another control box with the
> >same results. Has anyone else experienced this? Is there a fix?
> >
> >Thanks,
> >
> >Jim N0AV
>
>
>
> ------------------------------
>
> Message: 7
> Date: Sat, 10 Oct 2009 21:52:31 -0400
> From: <john at kk9a.com>
> Subject: Re: [TowerTalk] Chrome Moly Mast Pipes for sale
> To: <TOWERTALK at contesting.com>
> Cc: pstark at suddenlink.net
> Message-ID: <62964052AD014F318E67EC44CD5AEE4A at Office>
> Content-Type: text/plain; charset="iso-8859-1"
>
> I meant to say steel weighs 0.283 pounds / cubic inch.
>
> BTW, a solid mast is not much stronger than heavy wall tubing but a lot
> heavier.
>
>
> ----- Original Message -----
> From: <john at kk9a.com>
> To: <TOWERTALK at contesting.com>
> Cc: <pstark at suddenlink.net>
> Sent: Saturday, October 10, 2009 8:59 PM
> Subject: Re: [TowerTalk] Chrome Moly Mast Pipes for sale
>
>
> The weight of steel is approximately 0.283 pounds / sq inch. So 12" of 3"
> round weighs: pi * 1.5(sq) * 12 * .283 = 24 pounds
>
> John KK9A
>
>
>
> To: <towertalk at contesting.com>
> Subject: Re: [TowerTalk] Chrome Moly Mast Pipes for sale
> From: "Pete Stark K4OM" <
> Date: Sat, 10 Oct 2009 19:38:41 -0400
> List-post: <towertalk at contesting.com">mailto:towertalk at contesting.com>
>
> What does a 3" solid rod weigh per foot?
> And what do you plan to hang on it?
>
> Pete K4OM
>
>
>
> ------------------------------
>
> Message: 8
> Date: Sat, 10 Oct 2009 20:59:24 -0700
> From: "Rick Karlquist" <richard at karlquist.com>
> Subject: Re: [TowerTalk] US Tower install - help request
> To: "Mat Eshpeter" <kk1c at live.com>
> Cc: towertalk at contesting.com
> Message-ID:
> <9aafa53806853c62439e782217499799.squirrel at webmail.sonic.net>
> Content-Type: text/plain;charset=iso-8859-1
>
> >> AFAIK, it is *crucial* to do it as specified with regard to "undisturbed
> >> soil". In other words, they do not want you to dig a hole,
> >> form it up, backfill behind it and pour. They want a plain ol' hole in
> >> the dirt, with the concrete/rebar in it. And, that may be where
> >> the biggest danger lies, digging an 8' deep hole, straight down. I was
>
> I had a 6 foot diameter round hole dug by a drilling rig
> with an auger type bit. No problem to go straight down 9 ft,
> or 49 feet.
>
> Rick N6RK
>
>
>
> ------------------------------
>
> Message: 9
> Date: Sat, 10 Oct 2009 21:36:14 -0700
> From: Michael Dinkelman <mwdink at eskimo.com>
> Subject: [TowerTalk] Half-Square Guidance
> To: Towertalk <towertalk at contesting.com>
> Message-ID: <4AD160BE.4030802 at eskimo.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Hello All
>
> So, between my two towers, it appears I may have enough room
> to put up a half-square for 80 meters. I've read the info in the
> antenna book but still have a couple of questions that weren't
> really addressed there. Rather than waste some valuable time,
> maybe others have addressed them.
>
> 1) As I said, the two supports would be 60+ foot towers. As such,
> the vertical portions would parallel the towers. I expect that might be
> a problem. (I wouldn't normally try to put a vertical next to another
> metal structure and a half square is essentially two phased verticals.)
> I could make the verticals slant away from the tower. The literature
> indicates that shouldn't have much effect on performance but I'm not
> sure it would prevent the tower from affecting the antenna.
>
> 2) Providing the above isn't an issue, can I use one tower as the apex
> of two separate half-squares? (see below) One going in one direction
> and another maybe 90 degrees off? (That would seem to be a problem
> as the two would be resonant at the same frequencies and I see
> coupling issues.)
>
> O---------------------O
> O
> |
> |
> |
> |
> O
>
> cheers
> dink, n7wa
>
>
>
>
> ------------------------------
>
> Message: 10
> Date: Sat, 10 Oct 2009 19:36:50 -0000
> From: "Jim Hargrave" <w5ifp at gvtc.com>
> Subject: Re: [TowerTalk] Need: Hy Gain TH6DX Manual (PDF)
> To: "Tom Menas" <k3wt at yahoo.com>
> Cc: Tower Talk <towertalk at contesting.com>
> Message-ID: <DCECKDJAOBPBLOFNKPLFGECBCMAA.w5ifp at gvtc.com>
> Content-Type: text/plain; charset="us-ascii"
>
> Attached..
>
> * 73's Jim W5IFP *
> w5ifp at gvtc.com
>
>
> >-----Original Message-----
> >From: towertalk-bounces at contesting.com
> >[mailto:towertalk-bounces at contesting.com]On Behalf Of Tom Menas
> >Sent: Saturday, October 10, 2009 1:37 PM
> >To: Tower Talk
> >Subject: [TowerTalk] Need: Hy Gain TH6DX Manual (PDF)
> >
> >
> >I'm trying to help YS1SF get parts for his TH6DX and need a PDF
> >of the TH6DX manual.
> >
> >Does anyone have one to e-mail me?
> >
> >Tnx,
> >
> >Tom, K3WT
> >
> >
> >
> >
> >_______________________________________________
> >
> >
> >
> >_______________________________________________
> >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
>
>
> End of TowerTalk Digest, Vol 82, Issue 17
> *****************************************
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