[TowerTalk] Rohn 25G Tower
Roger (K8RI)
K8RI-on-TowerTalk at tm.net
Mon Nov 12 19:49:40 EST 2007
>I have installed over 85 Rohn 25G towers in the past 30 years. Many have
>been 40-50 foot with the proper base and no guy wires. These have been for
>the CB'ers and Ham radio operators. These also have anywhere between 3 & 6
>element beams. Never have heard of a problem with any of these. I know of a
>70 foot Rohn 25G tower that has a 4 element Moonraker beam with no guy
>wires. It has a 5'x5'x5' concrete base and still standing after 25 years of
>North Louisiana weather.
> Ok, back to reality. With good solid ground. Not sandy or marshy ground.
> And the proper hole dug 3'x3'x4' with a >foot of gravel in the bottom and
> a 1"x6" form around the top. A few pieces of concrete wire wrapped between
> the >tower and earth. This will be suffice for a 40 foot non-guyed tower.
> With a moderate beam. Been there done that.
Yes it works in many cases. I've used dirt bases on guyed 25 G and ROHN used
to make them. I had a 5L KLM 20 Meter monobander on top of a 40 footer with
a dirt base, bracketed to the end of the house at 12 feet, and light weight
guys. That system stood when the winds tore a TV antenna and tripod mount
off the roof . It was lag bolted to the rafters. I'll probably use dirt
bases on bracketed and/or guyed 25G to 40 feet or so again, but they do not
meet the ROHN specs and from that alone I'd not recomend the practice to any
one else. In areas requiring building permits and engineered installations
they'd never pass muster either.
A 70 foot 25G may have stood for years without guys, but if you do the
calculations for yield strength it's an accident just waiting to happen.
Roger (K8RI)
>
> W5KGT
> Calhoun,La.
>
> ----- Original Message -----
> From: towertalk-request at contesting.com
> To: towertalk at contesting.com
> Sent: Sunday, November 11, 2007 10:12:00 PM (GMT-0600) America/Chicago
> Subject: TowerTalk Digest, Vol 59, Issue 36
>
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> Today's Topics:
>
> 1. Re: Installation Rohn 25G (David Calder)
> 2. F12 EF-140S (Phil Snyder)
> 3. Re: Installation Rohn 25G (D. Scott MacKenzie)
> 4. Re: Installation Rohn 25G (AD5VJ Bob)
> 5. Re: Installation Rohn 25G (AD5VJ Bob)
> 6. Re: F12 EF-140S (Ed Muns)
> 7. Re: Installation Rohn 25G (AD5VJ Bob)
> 8. Re: Microdem Terrain Files (Gary Slagel)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sun, 11 Nov 2007 20:06:54 -0500
> From: "David Calder" <n4zkf at n4zkf.com>
> Subject: Re: [TowerTalk] Installation Rohn 25G
> To: "'Roger (K8RI)'" <K8RI-on-TowerTalk at tm.net>, "'TowerTalk'"
> <towertalk at contesting.com>
> Message-ID: <jxkrnxrq17paclb.111120072005 at n4zkf.com>
> Content-Type: text/plain; charset="us-ascii"
>
>
> Look at the following link.
>
> http://www.n4zkf.com/shack.htm
>
> Scroll to the bottom. The two towers you see. Both are 40' Rohn 25 "not
> guyed".
> 1 has a A3S tribander, a 12 el 2 meter SSB AND a 24 el 440 SSB antenna on
> it.
>
> The other has a 6 Meter beam, stacked 2 meter beams and an omni.
>
> Now, they are tied at 10' with a house bracket on the roof. But they are
> NOT GUYED. Google earth my QTH and you will see I live 1000' off the ocean
> beachside, saw
> 3 hurricanes in as many weeks come right over top of me a few years ago
> and
> they
> are both standing. What can I say.
>
> 73 Dave
> n4zkf
>
>
> -----Original Message-----
> From: towertalk-bounces at contesting.com
> [mailto:towertalk-bounces at contesting.com] On Behalf Of Roger (K8RI)
> Sent: Sunday, November 11, 2007 6:24 PM
> To: AD5VJ Bob; towertalk at contesting.com
> Subject: Re: [TowerTalk] Installation Rohn 25G
>
>
>
>
>> Just so no one thinks I am crazy :)
>>
>> A couple of guys have talked about needing guy wires. and that
>> probably many others would say the same thing:
>>
>> I do plan on putting guy wires on but just cant afford them right now.
>> I will add them after I get it all up in the air.
>>
>
> Just for a bit of clarification:
> After reading the previous postes I'm a little confused. How high are you
> going before you put up the antennas and guys?
> That size base isn't suficient to hold a 40 foot 25G and tribander without
> guys except on a very calm day. I'd also be apprehensive about climbing 40
> a
> foot 25G without guys even on a calm day.
>
> Fortunately 40 feet and a small tribander don't take an elaborate base and
> guy system which becomes much more substantial in a hurry as you add
> height.
>
> I have a rather simple and effective, but heavy gin pole I constructed.
> If
> I can find everything I'll try and shoot some photos and put them up on
> my
> site.
>
> Good Luck and be careful.
>
> Roger (K8RI)
>> Problem is, I was off work for two and a half weeks due to shoulder
>> and neck problems so our paycheck is very limited right now. I am back
>> to work so should be able to do the over time to be able to afford
>> them in a month or so.
>>
>> I have to figure out a way to make a gin pole to get the other
>> sections up so while I am doing that I figured I would put the base in
>> the ground to set good. and then probably to the guy wires after that.
>>
>> Bob AD5VJ
>
> _______________________________________________
>
>
>
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> http://lists.contesting.com/mailman/listinfo/towertalk
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>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Sun, 11 Nov 2007 19:17:40 -0600
> From: Phil Snyder <n9lah at comcast.net>
> Subject: [TowerTalk] F12 EF-140S
> To: towertalk at contesting.com
> Message-ID: <4737A9B4.5020302 at comcast.net>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> I have the antenna mentioned in the subject line. I purchased it used
> about a year ago. I never really got around to checking it out. I have
> now tried to assemble it as a stand alone dipole. The problem I have is
> that it only came with the bracket to mount to the boom of a C-3 and not
> the plate with riser to hold the linear loading when assembled as a
> dipole. For those familiar with the antenna, can I just fabricate a
> small plate to mount the spreader on the mast above the antenna? It
> almost looks like too simple an idea to work.
>
> Phil
> N9LAH
>
>
> ------------------------------
>
> Message: 3
> Date: Sun, 11 Nov 2007 20:31:53 -0500
> From: "D. Scott MacKenzie" <kb0fhp at comcast.net>
> Subject: Re: [TowerTalk] Installation Rohn 25G
> To: "David Calder" <n4zkf at n4zkf.com>, "'Roger (K8RI)'"
> <K8RI-on-TowerTalk at tm.net>, "'TowerTalk'"
> <towertalk at contesting.com>
> Message-ID: <IBEHKIPNPADIIAMAJNHNOEDOGCAA.kb0fhp at comcast.net>
> Content-Type: text/plain; charset="us-ascii"
>
> Bracketing makes all the difference in the world. Looking at the Rohn
> catalog, it makes a huge difference in the load carrying capacity whether
> they are freestanding or bracketed. Your results do not surprise me at
> all....
>
> -----Original Message-----
> From: towertalk-bounces at contesting.com
> [mailto:towertalk-bounces at contesting.com]On Behalf Of David Calder
> Sent: Sunday, November 11, 2007 8:07 PM
> To: 'Roger (K8RI)'; 'TowerTalk'
> Subject: Re: [TowerTalk] Installation Rohn 25G
>
>
>
> Look at the following link.
>
> http://www.n4zkf.com/shack.htm
>
> Scroll to the bottom. The two towers you see. Both are 40' Rohn 25 "not
> guyed".
> 1 has a A3S tribander, a 12 el 2 meter SSB AND a 24 el 440 SSB antenna on
> it.
>
> The other has a 6 Meter beam, stacked 2 meter beams and an omni.
>
> Now, they are tied at 10' with a house bracket on the roof. But they are
> NOT GUYED. Google earth my QTH and you will see I live 1000' off the ocean
> beachside, saw
> 3 hurricanes in as many weeks come right over top of me a few years ago
> and
> they
> are both standing. What can I say.
>
> 73 Dave
> n4zkf
>
>
> -----Original Message-----
> From: towertalk-bounces at contesting.com
> [mailto:towertalk-bounces at contesting.com] On Behalf Of Roger (K8RI)
> Sent: Sunday, November 11, 2007 6:24 PM
> To: AD5VJ Bob; towertalk at contesting.com
> Subject: Re: [TowerTalk] Installation Rohn 25G
>
>
>
>
>> Just so no one thinks I am crazy :)
>>
>> A couple of guys have talked about needing guy wires. and that
>> probably many others would say the same thing:
>>
>> I do plan on putting guy wires on but just cant afford them right now.
>> I will add them after I get it all up in the air.
>>
>
> Just for a bit of clarification:
> After reading the previous postes I'm a little confused. How high are you
> going before you put up the antennas and guys?
> That size base isn't suficient to hold a 40 foot 25G and tribander without
> guys except on a very calm day. I'd also be apprehensive about climbing 40
> a
> foot 25G without guys even on a calm day.
>
> Fortunately 40 feet and a small tribander don't take an elaborate base and
> guy system which becomes much more substantial in a hurry as you add
> height.
>
> I have a rather simple and effective, but heavy gin pole I constructed.
> If
> I can find everything I'll try and shoot some photos and put them up on
> my
> site.
>
> Good Luck and be careful.
>
> Roger (K8RI)
>> Problem is, I was off work for two and a half weeks due to shoulder
>> and neck problems so our paycheck is very limited right now. I am back
>> to work so should be able to do the over time to be able to afford
>> them in a month or so.
>>
>> I have to figure out a way to make a gin pole to get the other
>> sections up so while I am doing that I figured I would put the base in
>> the ground to set good. and then probably to the guy wires after that.
>>
>> Bob AD5VJ
>
> _______________________________________________
>
>
>
> _______________________________________________
> 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: 4
> Date: Sun, 11 Nov 2007 19:38:45 -0600
> From: "AD5VJ Bob" <rtnmi at sbcglobal.net>
> Subject: Re: [TowerTalk] Installation Rohn 25G
> To: "'Mike, K6BR'" <noddy1211 at sbcglobal.net>,
> <towertalk at contesting.com>
> Message-ID: <0b4901c824cc$c59788f0$6401a8c0 at D9FBHB71>
> Content-Type: text/plain; charset="US-ASCII"
>
> Hi guys:
>
> Ok I think what I am going to do after all of this is simply install the
> base, stabilize it so it sets up and then wait until I can
> afford to do the rest.
>
> Thanks to one and all not only for the advice but for the noticeable
> concern.
>
> I will take it all to heart and wait a bit on the rest of the install.
>
> Now the only thing I cant seem to locate is the PDF for the freestanding
> specs for 40 feet.
>
> Can someone pls send the url for that, I looked but cant seem to find it.
>
> Sincerely.
> Bob AD5VJ
>
>> -----Original Message-----
>> From: towertalk-bounces at contesting.com
>> [mailto:towertalk-bounces at contesting.com] On Behalf Of Mike, K6BR
>> Sent: Sunday, November 11, 2007 6:54 PM
>> To: towertalk at contesting.com
>> Subject: Re: [TowerTalk] Installation Rohn 25G
>>
>> The post below is the best advice you have had so far. You
>> have to plan for the unexpected.
>>
>> Back when I lived in the UK the top 10 feet or so of the
>> tower came crashing into the roof of the house in a freak 104
>> MPH wind one night, with just a Cushcraft A3 on it, this was
>> a temper installation and guyed with rope.
>>
>> I was young eager and stupid, but I sure learned my lesson
>> (1,000 pounds sterling later:-)
>>
>> Mike
>>
>> -----Original Message-----
>>
>>
>> The line between AMATEUR and doing it right comes in to play
>> with towers.
>>
>> 25G may be self supporting for a small TV antenna. Dont even
>> think you can get away with a tribander.
>>
>> Do your self a real favor... Wait until you can do it right
>> and safely.
>> You'll get to enjoy the results
>> a whole lot longer. Compared to the cost of an antenna, not
>> to mention lives, guy wires and anchors are cheap.
>>
>> Bill
>> K2EK
>>
>>
>>
>>
>>
>> ************************************** See what's new at
>> http://www.aol.com _______________________________________________
>>
>>
>>
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>>
>>
>>
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>
>
>
> ------------------------------
>
> Message: 5
> Date: Sun, 11 Nov 2007 19:52:09 -0600
> From: "AD5VJ Bob" <rtnmi at sbcglobal.net>
> Subject: Re: [TowerTalk] Installation Rohn 25G
> To: <towertalk at contesting.com>
> Message-ID: <0b5d01c824ce$a71f7a20$6401a8c0 at D9FBHB71>
> Content-Type: text/plain; charset="US-ASCII"
>
> One thing I dont yet understand:
>
> Why does the house bracketing seem to make such a big difference?
>
> Is it equivalent to putting in the ground further thereby lowering the
> balance point or does it stabilize it from vibration that
> much or what?
>
> Bob AD5VJ
>
>
>
> ------------------------------
>
> Message: 6
> Date: Sun, 11 Nov 2007 18:17:59 -0800
> From: "Ed Muns" <w0yk at msn.com>
> Subject: Re: [TowerTalk] F12 EF-140S
> To: "'Phil Snyder'" <n9lah at comcast.net>
> Cc: towertalk at contesting.com
> Message-ID: <BAYC1-PASMTP114664D24030995A6C62A590870 at CEZ.ICE>
> Content-Type: text/plain; charset="us-ascii"
>
>> I have the antenna mentioned in the subject line. I purchased
>> it used about a year ago. I never really got around to
>> checking it out. I have now tried to assemble it as a stand
>> alone dipole. The problem I have is that it only came with
>> the bracket to mount to the boom of a C-3 and not the plate
>> with riser to hold the linear loading when assembled as a
>> dipole. For those familiar with the antenna, can I just
>> fabricate a small plate to mount the spreader on the mast
>> above the antenna? It almost looks like too simple an idea to work.
>
> You can certainly mount the loading wire support to the mast. But that
> means you will have to assembly half of the linear loading wires on the
> tower to get them on the opposite side of the mast.
>
> Another approach is to the boom bracket and mount the element on the end
> of
> a short 3' "boom". The other end of the "boom" would be mounted to the
> mast
> with a standard technique of U-bolts and an aluminum plate. The reason
> for
> this is so the element can be self-contained and tuned without
> disassembling
> half of the linear loading wires to get it on/off the mast.
>
> 73,
> Ed - W0YK
>
>
>
> ------------------------------
>
> Message: 7
> Date: Sun, 11 Nov 2007 20:27:23 -0600
> From: "AD5VJ Bob" <rtnmi at sbcglobal.net>
> Subject: Re: [TowerTalk] Installation Rohn 25G
> To: "'AD5VJ Bob'" <rtnmi at sbcglobal.net>, <towertalk at contesting.com>
> Message-ID: <0b6401c824d3$8fd24280$6401a8c0 at D9FBHB71>
> Content-Type: text/plain; charset="US-ASCII"
>
> ok found the file thanks for all the help fellows
>
> Bob AD5VJ
>
>> -----Original Message-----
>> From: towertalk-bounces at contesting.com
>> [mailto:towertalk-bounces at contesting.com] On Behalf Of AD5VJ Bob
>> Sent: Sunday, November 11, 2007 7:52 PM
>> To: towertalk at contesting.com
>> Subject: Re: [TowerTalk] Installation Rohn 25G
>>
>> One thing I dont yet understand:
>>
>> Why does the house bracketing seem to make such a big difference?
>>
>> Is it equivalent to putting in the ground further thereby
>> lowering the balance point or does it stabilize it from
>> vibration that much or what?
>>
>> Bob AD5VJ
>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>
>
>
> ------------------------------
>
> Message: 8
> Date: Sun, 11 Nov 2007 20:11:54 -0800 (PST)
> From: Gary Slagel <gdslagel at yahoo.com>
> Subject: Re: [TowerTalk] Microdem Terrain Files
> To: towertalk at contesting.com
> Message-ID: <108227.95061.qm at web52610.mail.re2.yahoo.com>
> Content-Type: text/plain; charset=iso-8859-1
>
> Thanks Jerry,
>
> Think I'll forget YT and wait the few days for the new Antenna book and
> HFTA to arrive!
>
>
>
> K4SAV <RadioIR at charter.net> wrote:
> For HFTA, on the first line of the ".pro" file, put the word feet or
> meters, depending on your data. I'm not sure how YT works.
>
> Jerry, K4SAV
>
> Gary Slagel wrote:
>
>>Hi,
>>
>> I downloaded Microdem and DEM data and have generated terrain files....
>> worked great! I've ordered a new antenna book so I'll have the HFTA
>> program to use with the terrain files but in the mean time I'd like to
>> run YT against my terrain files.
>>
>> Looks like, even though I set my units in Microdem to feet, the terrain
>> files are generated in meters. I'm not sure if HFTA will handle meters
>> but it looks like YT expects feet to be used in the terrain files. Has
>> anyone run into this and come up with a simple solution? My best solution
>> right now is to take them to work with me where I can dump them to a unix
>> box and write a script to do the conversion but thought I might be
>> missing something and there might be a simple work around.
>>
>> Thanks for advice,
>> Gary
>>
>>
>>Gary Slagel/N0SXX
>>Lakewood, CO
>>http://marina.fortunecity.com/sanpedro/351
>>
>>
>
> _______________________________________________
>
>
>
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>
>
> Gary Slagel/N0SXX
> Lakewood, CO
> http://marina.fortunecity.com/sanpedro/351
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>
> End of TowerTalk Digest, Vol 59, Issue 36
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