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Tower design
I am trying to find information on build your own tower. As retirement
nears I plan on having a lot more time for doing things like this and will have a few acres I can devote to an antenna farm. I wouldnt mind learning to design them from scratch but would prefer a computer program if one is available. I know to some building your own tower may not seem practical but my wife and I inherited a lot of the basic materials when her father passed away. I am especialy interested in building tubular foldover mast 50 to 70 ft tall. It seems like years ago I came across a magazine article on this that also had associated design software. Any help would be greatly appreciated. Jimmie |
Tower design
Dear Jimmie (no call sign given):
Even towers as short, and as relatively simple as what you say you are considering, involve safety of life issues! Very expensive computer programs exist that will analyze a tower, however no professional trusts them until comparing what the program exports with what is calculated using a hand-calculator and fundamental concepts. Textbooks on (mechanical) statics and strength-of-materials would be appropriate places to start. Even a spread sheet can be used to develop computational tools, though a real HP calculator can be a great aid. A good mechanical engineering handbook (Mark's ?) might have the information, but might be more difficult to read. Schaum's Outline series might be better than some textbooks. Of course, you may have this sort of background already. If you stay below 70 feet and have trees/buildings all around, wind loading calculations are relatively simple. (The standard (222G) on calculating serious wind loads cost about $400.) Give the group more of an idea of the "boundary conditions" for your proposal. How wonderful to be able to contemplate having time for such a project in retirement. Regards, Mac N8TT -- J. Mc Laughlin; Michigan U.S.A. Home: "JIMMIE" wrote in message oups.com... I am trying to find information on build your own tower. As retirement nears I plan on having a lot more time for doing things like this and will have a few acres I can devote to an antenna farm. I wouldnt mind learning to design them from scratch but would prefer a computer program if one is available. I know to some building your own tower may not seem practical but my wife and I inherited a lot of the basic materials when her father passed away. I am especialy interested in building tubular foldover mast 50 to 70 ft tall. It seems like years ago I came across a magazine article on this that also had associated design software. Any help would be greatly appreciated. Jimmie |
Tower design
"J. Mc Laughlin" wrote in message .. . Dear Jimmie (no call sign given): Even towers as short, and as relatively simple as what you say you are considering, involve safety of life issues! Very expensive computer programs exist that will analyze a tower, however no professional trusts them until comparing what the program exports with what is calculated using a hand-calculator and fundamental concepts. Textbooks on (mechanical) statics and strength-of-materials would be appropriate places to start. Even a spread sheet can be used to develop computational tools, though a real HP calculator can be a great aid. A good mechanical engineering handbook (Mark's ?) might have the information, but might be more difficult to read. Schaum's Outline series might be better than some textbooks. Of course, you may have this sort of background already. If you stay below 70 feet and have trees/buildings all around, wind loading calculations are relatively simple. (The standard (222G) on calculating serious wind loads cost about $400.) Give the group more of an idea of the "boundary conditions" for your proposal. How wonderful to be able to contemplate having time for such a project in retirement. Regards, Mac N8TT -- J. Mc Laughlin; Michigan U.S.A. Home: "JIMMIE" wrote in message oups.com... I am trying to find information on build your own tower. As retirement nears I plan on having a lot more time for doing things like this and will have a few acres I can devote to an antenna farm. I wouldnt mind learning to design them from scratch but would prefer a computer program if one is available. I know to some building your own tower may not seem practical but my wife and I inherited a lot of the basic materials when her father passed away. I am especialy interested in building tubular foldover mast 50 to 70 ft tall. It seems like years ago I came across a magazine article on this that also had associated design software. Any help would be greatly appreciated. Jimmie Antenna will have to be tall enough to clear the current canopy of oaks that cover the property. Materials I have on had are way more heavy duty than what you see towers normaly built of. such as several sections of galvanised sign post The heavy U shaped stuf with the flange, dont know what you call it but there is probably 300 to 400 ft of this stuff, lots of rebar. I could easily build something similar to a Rohn tower with this. Also have a MIG and Stick welder. There is maybe 2000ft of oil well drilling pipe piled up out there. Wife pretty much mandated that I do something with it or get rid of it. She has her ticket too so she is sympathetic to the cause. Ther is also a neighbor who works on heavy equipment and he has a crane. Wonder what a few steaks and beers will get me. First I would like to get up my VHF/UHF stuff. Nothing elaborate here just some stacked Yagi on 2M and 432 and a 5 elemnt Yagi for 6M. The is also a lot of tublar steel some about 6 inches in daimeter. with inch thick walls, I think he was making TVRO mast out of this stuff at one time. Hopefully once I get the place cleaned up I might start a second career, there is a big 30 x 60 ft shop on the property that should be good for something. Oh, yes I do have a 50ft Rohn tower i was thinking about tempoaraly erecting thi as a scafold to work off of. Just a thought. With the oil well pipe I was planning on making a base from three pieces of it the screw on three pieces and weld bracing on as I go up it then add on three more pieces and keep going up. I figure I should easily build a 65 ft tower this way, maybe more. There are also some really tall southern long leaf pines about 30 years old on the prperty that might be good for something. These are some of the taler trees and I was thinking about stringinging soem 75/80M dipoles of of these. If I had some design info I might could start figuring out how to make the best use of some of this junk and get a head start on the game. Jimmie |
Tower design
Jimmie D wrote:
"J. Mc Laughlin" wrote in message .. . Dear Jimmie (no call sign given): Even towers as short, and as relatively simple as what you say you are considering, involve safety of life issues! Very expensive computer programs exist that will analyze a tower, however no professional trusts them until comparing what the program exports with what is calculated using a hand-calculator and fundamental concepts. Textbooks on (mechanical) statics and strength-of-materials would be appropriate places to start. Even a spread sheet can be used to develop computational tools, though a real HP calculator can be a great aid. A good mechanical engineering handbook (Mark's ?) might have the information, but might be more difficult to read. Schaum's Outline series might be better than some textbooks. Of course, you may have this sort of background already. If you stay below 70 feet and have trees/buildings all around, wind loading calculations are relatively simple. (The standard (222G) on calculating serious wind loads cost about $400.) Give the group more of an idea of the "boundary conditions" for your proposal. How wonderful to be able to contemplate having time for such a project in retirement. Regards, Mac N8TT -- J. Mc Laughlin; Michigan U.S.A. Home: "JIMMIE" wrote in message oups.com... I am trying to find information on build your own tower. As retirement nears I plan on having a lot more time for doing things like this and will have a few acres I can devote to an antenna farm. I wouldnt mind learning to design them from scratch but would prefer a computer program if one is available. I know to some building your own tower may not seem practical but my wife and I inherited a lot of the basic materials when her father passed away. I am especialy interested in building tubular foldover mast 50 to 70 ft tall. It seems like years ago I came across a magazine article on this that also had associated design software. Any help would be greatly appreciated. Jimmie Antenna will have to be tall enough to clear the current canopy of oaks that cover the property. Materials I have on had are way more heavy duty than what you see towers normaly built of. such as several sections of galvanised sign post The heavy U shaped stuf with the flange, dont know what you call it but there is probably 300 to 400 ft of this stuff, lots of rebar. I could easily build something similar to a Rohn tower with this. Also have a MIG and Stick welder. There is maybe 2000ft of oil well drilling pipe piled up out there. Wife pretty much mandated that I do something with it or get rid of it. She has her ticket too so she is sympathetic to the cause. Ther is also a neighbor who works on heavy equipment and he has a crane. Wonder what a few steaks and beers will get me. First I would like to get up my VHF/UHF stuff. Nothing elaborate here just some stacked Yagi on 2M and 432 and a 5 elemnt Yagi for 6M. The is also a lot of tublar steel some about 6 inches in daimeter. with inch thick walls, I think he was making TVRO mast out of this stuff at one time. Hopefully once I get the place cleaned up I might start a second career, there is a big 30 x 60 ft shop on the property that should be good for something. Oh, yes I do have a 50ft Rohn tower i was thinking about tempoaraly erecting thi as a scafold to work off of. Just a thought. With the oil well pipe I was planning on making a base from three pieces of it the screw on three pieces and weld bracing on as I go up it then add on three more pieces and keep going up. I figure I should easily build a 65 ft tower this way, maybe more. There are also some really tall southern long leaf pines about 30 years old on the prperty that might be good for something. These are some of the taler trees and I was thinking about stringinging soem 75/80M dipoles of of these. If I had some design info I might could start figuring out how to make the best use of some of this junk and get a head start on the game. Jimmie Jimmie; If you are planning to use any of the materials you list here I wouldn't want to be in the same county. All of the items you list are of low tensile strength. The well casing will fold over when you try to crank it up. I know from actual testing. My ELMER had a hundred feet of 6 inch pipe. We put his tribander on the top end and hooked a wench to the bottom. After one hell of a lot of cranking we turned around to see how much more we had to go to put straight up. The tribander was still on the ground and the bottom of the tower was vertical. The pipe had folded at the hinge point. Rebar is good for concrete and stakes but not much else. Fence posts are extremely bendable. For your safety forget about your scrap steel and buy a commercial manufactured tower. Dave WD9BDZ |
Tower design
On 11 Mar 2007 07:44:30 -0700, "JIMMIE"
wrote: I am trying to find information on build your own tower. As retirement nears I plan on having a lot more time for doing things like this and will have a few acres I can devote to an antenna farm. I wouldnt mind learning to design them from scratch but would prefer a computer program if one is available. I know to some building your own tower may not seem practical but my wife and I inherited a lot of the basic materials when her father passed away. I am especialy interested in building tubular foldover mast 50 to 70 ft tall. It seems like years ago I came across a magazine article on this that also had associated design software. Any help would be greatly appreciated. Jimmie I have a Wilson crank up mast that I purchased in about 1980. It was originally a 77 foot tower but a failure early in its life led to removal of the top section. The failure was due to a torsional load (48 element collinear on 440mhz) and other antennas. The section that failed was about 3 inches in diameter. I appears to be pretty much the same as what US Tower is selling today. I have performed needed maintenance through the years and even moved it from Ohio to North Carolina. In Ohio it was installed as a guyed tower. It is currently installed un guyed with a home brew device that allows me to lay it over to work on antennas on the ground. I feel that every aspect of the mechanism is critical. If it was any heavier the electric boat winch could not handle the extent ion. If I had much more weight on the top, the lay over wench (and I-Beam) would be challenged. It is built just loose enough to not hang on retraction but not rattle excessively in the wind. I don't even want to think about what would happen if it jammed on retraction! The galvanizing is worn off the outside but still in good shape on the inside. I have replaced a couple of the pulleys and one of the cables along with miscellaneous clips & such. When you deal with this thing it is better to think in terms of a sailboat mast rather than a tower. Most loads you apply try to put a crease in the tubing or load the extent ion cables. Your suggested project would require more patience that I have. It only takes a few hours of welding for me to want to do something else! I would sell the old tubing & buy a new crank up mast. BTW, I am currently trying to figure out how I can safely plant a 40 foot utility pole that was a gift.... John Ferrell W8CCW "Life is easier if you learn to plow around the stumps" |
Tower design
"John Ferrell" wrote in message ... On 11 Mar 2007 07:44:30 -0700, "JIMMIE" wrote: I am trying to find information on build your own tower. As retirement nears I plan on having a lot more time for doing things like this and will have a few acres I can devote to an antenna farm. I wouldnt mind learning to design them from scratch but would prefer a computer program if one is available. I know to some building your own tower may not seem practical but my wife and I inherited a lot of the basic materials when her father passed away. I am especialy interested in building tubular foldover mast 50 to 70 ft tall. It seems like years ago I came across a magazine article on this that also had associated design software. Any help would be greatly appreciated. Jimmie I have a Wilson crank up mast that I purchased in about 1980. It was originally a 77 foot tower but a failure early in its life led to removal of the top section. The failure was due to a torsional load (48 element collinear on 440mhz) and other antennas. The section that failed was about 3 inches in diameter. I appears to be pretty much the same as what US Tower is selling today. I have performed needed maintenance through the years and even moved it from Ohio to North Carolina. In Ohio it was installed as a guyed tower. It is currently installed un guyed with a home brew device that allows me to lay it over to work on antennas on the ground. I feel that every aspect of the mechanism is critical. If it was any heavier the electric boat winch could not handle the extent ion. If I had much more weight on the top, the lay over wench (and I-Beam) would be challenged. It is built just loose enough to not hang on retraction but not rattle excessively in the wind. I don't even want to think about what would happen if it jammed on retraction! The galvanizing is worn off the outside but still in good shape on the inside. I have replaced a couple of the pulleys and one of the cables along with miscellaneous clips & such. When you deal with this thing it is better to think in terms of a sailboat mast rather than a tower. Most loads you apply try to put a crease in the tubing or load the extent ion cables. Your suggested project would require more patience that I have. It only takes a few hours of welding for me to want to do something else! I would sell the old tubing & buy a new crank up mast. BTW, I am currently trying to figure out how I can safely plant a 40 foot utility pole that was a gift.... John Ferrell W8CCW "Life is easier if you learn to plow around the stumps" I dont intend to make anything that will crank up, tilt over is a consideration as I once saw a magazine article with design parameters and understand the person who wrote the article also may have written software. I have set a light pole before. I got theinfo from the local power company on how much of it should be buried and a friend that has a wrcker helped me put it in he ground. Since the bottom end is considerably heavier than the top the center of gravity is much lower than the actual center. this makes things a lot easier than it may appear. Hardest part by far was digging the hole. Jimmie |
Tower design
On Mar 11, 7:44 am, "JIMMIE" wrote:
I am trying to find information on build your own tower. As retirement nears I plan on having a lot more time for doing things like this and will have a few acres I can devote to an antenna farm. I wouldnt mind learning to design them from scratch but would prefer a computer program if one is available. I know to some building your own tower may not seem practical but my wife and I inherited a lot of the basic materials when her father passed away. I am especialy interested in building tubular foldover mast 50 to 70 ft tall. It seems like years ago I came across a magazine article on this that also had associated design software. Any help would be greatly appreciated. Jimmie k6mhe.com/n7ws/PipeMastDesign.pdf |
Tower design
On Mar 14, 6:15 pm, "Wes" wrote:
On Mar 11, 7:44 am, "JIMMIE" wrote: I am trying to find information on build your own tower. As retirement nears I plan on having a lot more time for doing things like this and will have a few acres I can devote to an antenna farm. I wouldnt mind learning to design them from scratch but would prefer a computer program if one is available. I know to some building your own tower may not seem practical but my wife and I inherited a lot of the basic materials when her father passed away. I am especialy interested in building tubular foldover mast 50 to 70 ft tall. It seems like years ago I came across a magazine article on this that also had associated design software. Any help would be greatly appreciated. Jimmie k6mhe.com/n7ws/PipeMastDesign.pdf Thanks Wes this is the info I needed, as a matter of fact it IS the magazine article I remember reading. I keep thinking that after the article came out the author published software to go along with it, do you know anything about this? Jimmie |
Tower design
On Mar 14, 7:25 pm, "JIMMIE" wrote:
On Mar 14, 6:15 pm, "Wes" wrote: On Mar 11, 7:44 am, "JIMMIE" wrote: I am trying to find information on build your own tower. As retirement nears I plan on having a lot more time for doing things like this and will have a few acres I can devote to an antenna farm. I wouldnt mind learning to design them from scratch but would prefer a computer program if one is available. I know to some building your own tower may not seem practical but my wife and I inherited a lot of the basic materials when her father passed away. I am especialy interested in building tubular foldover mast 50 to 70 ft tall. It seems like years ago I came across a magazine article on this that also had associated design software. Any help would be greatly appreciated. Jimmie k6mhe.com/n7ws/PipeMastDesign.pdf Thanks Wes this is the info I needed, as a matter of fact it IS the magazine article I remember reading. I keep thinking that after the article came out the author published software to go along with it, do you know anything about this? Jimmie- Hide quoted text - - Show quoted text - That is a great website you sent me to, much morethan just the pdf file I was looking for. k6mhe.com/ |
Tower design
"JIMMIE" wrote in message oups.com... I am trying to find information on build your own tower. As retirement nears I plan on having a lot more time for doing things like this and will have a few acres I can devote to an antenna farm. I wouldnt mind learning to design them from scratch but would prefer a computer program if one is available. I know to some building your own tower may not seem practical but my wife and I inherited a lot of the basic materials when her father passed away. I am especialy interested in building tubular foldover mast 50 to 70 ft tall. It seems like years ago I came across a magazine article on this that also had associated design software. Any help would be greatly appreciated. Jimmie Go for it! http://www.funnyphotos.net.au/userim...169899532a.jpg |
Tower design
On Mar 16, 12:05 am, "Sal M. Onella"
wrote: "JIMMIE" wrote in message oups.com... I am trying to find information on build your own tower. As retirement nears I plan on having a lot more time for doing things like this and will have a few acres I can devote to an antenna farm. I wouldnt mind learning to design them from scratch but would prefer a computer program if one is available. I know to some building your own tower may not seem practical but my wife and I inherited a lot of the basic materials when her father passed away. I am especialy interested in building tubular foldover mast 50 to 70 ft tall. It seems like years ago I came across a magazine article on this that also had associated design software. Any help would be greatly appreciated. Jimmie Go for it! http://www.funnyphotos.net.au/userim...169899532a.jpg Your pic reminded me, somewhere in all the junk ther are 4 35 ft long steel street lamp poles. I know I have made the place sound like a junk yard but it isnt by a long way. Most of this stuff is inside a 30 x 60 ft building that you could drive a big motorhome into. Jimmie |
Tower design
I am trying to find information on build your own tower....
"Design Data for Pipe Masts", Ham Radio, July 1989, pp. 38 ff. "A One-Man Skyhook", QST, July 1947 pp. 19 ff. "A Sturdy 55-Ft. Skyhook", QST, October 1947, pp. 28 ff. "A Low-Cost Tilt-Over Tower", QST, November 1971, pp. 22 ff. "A 40 Foot Non-Conductive Sky-Hook", 73 Magazine, July 1968, pp. 16 ff. "Telescoping Antenna Mast", QST, March 1958, pp. 28 ff. "The Beam Pole", 73 Magazine, date not on torn-out article, pp. 24 ff. "A Self Supporting Antenna Mast", CQ, November 1962, pp. 44 ff. "A Foldover Cheapie", 73 Amateur Radio, September 1987, pp. 19 ff. "New Approach to the Fold-Over Tower", QST, date unknown, p. 36 "A Tilt-Over/Swivel Antenna Mount for Recreation Vehicles", 73 Amateur Radio Today, July 1993, pp. 28 ff. "A Self-Supporting Antenna Tower", QST, March 1941, pp. 18 ff. "A Counterweighted Antenna Tower", Radio, November 1941, pp. 44 ff. "Sixty Cents Per Foot", QST, June 1959, pp. 30 ff. "Lightweight Utility Mast", QST, July 1960, pp. 30 ff. "A Telescoping Mast, Mark II", WST, April 1966, pp. 96 ff. -- --Myron A. Calhoun; W0PBV; 2001 Dunbar Road; Manhattan, KS 66502-3907 Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge NRA Life Member & Certified Instructor for Rifle, Pistol, & Home Firearm Safety Also Certified Instructor for the Kansas Concealed-Carry Handgun (CCH) license |
Tower design
On Mar 14, 6:37 pm, "JIMMIE" wrote:
[snip] That is a great website you sent me to, much morethan just the pdf file I was looking for. k6mhe.com/ Yep, Danny has some good stuff there. I tried sending a similar message to this before but this horrible Google Groups swallowed it somewhere. Another related resource would be Leeson's book, "Physical Design of Yagi Antennas." Clearly, you are not designing a Yagi, but a lot of the material strength, deflection, wind loading, etc is applicable. There was also an Excel workbook offered by ARRL to accompany the book. I have it someplace, but can't lay my hand on it at the moment. Once you get the above ground part designed, you need to worry about the anchor too. Here's a link to a paper that might help the http://k6mhe.com/n7ws/SizeConcrete.doc Wes |
Tower design
On 16 Mar 2007 06:50:14 -0700, "Wes" wrote:
On Mar 14, 6:37 pm, "JIMMIE" wrote: [snip] That is a great website you sent me to, much morethan just the pdf file I was looking for. k6mhe.com/ Yep, Danny has some good stuff there. I tried sending a similar message to this before but this horrible Google Groups swallowed it somewhere. Another related resource would be Leeson's book, "Physical Design of Yagi Antennas." Clearly, you are not designing a Yagi, but a lot of the material strength, deflection, wind loading, etc is applicable. There was also an Excel workbook offered by ARRL to accompany the book. I have it someplace, but can't lay my hand on it at the moment. Once you get the above ground part designed, you need to worry about the anchor too. Here's a link to a paper that might help the http://k6mhe.com/n7ws/SizeConcrete.doc Wes Sometimes it is best to back into the correct answer... The suppliers are going to charge me for 5 yards of concrete in my area whether I use it or not... The other choice is to mix it myself. John Ferrell W8CCW "Life is easier if you learn to plow around the stumps" |
Tower design
Sometimes it is best to back into the correct answer... The suppliers
are going to charge me for 5 yards of concrete in my area whether I use it or not... The other choice is to mix it myself. John Ferrell W8CCW "Life is easier if you learn to plow around the stumps" It was about the same around here. I only wanted about a yard and where I wanted it a truck could not get in very easy. Had 50 bags (90 lb bags) delivered for around $ 300. Then rented a mixer for about $ 40. Spent about 6 hours transporting the bags with my riding lawnmower and cart about 150 feet to the tower hole and mixing it up and then cleaning the mixer. I did have water and electricity at the hole. Only put one bag in the mixer at a time as that was all I thought I could handle by myself. Used 43 bags in the tower and spent another part of a day putting the other bags in holes and pipes for the guy wires. It would have been cheeper to just get a load delivered and much faster, but just could not get a truck back there and I just could not see wheelborrowing it to the hole . |
Tower design
John Ferrell wrote:
On 16 Mar 2007 06:50:14 -0700, "Wes" wrote: On Mar 14, 6:37 pm, "JIMMIE" wrote: [snip] That is a great website you sent me to, much morethan just the pdf file I was looking for. k6mhe.com/ Yep, Danny has some good stuff there. I tried sending a similar message to this before but this horrible Google Groups swallowed it somewhere. Another related resource would be Leeson's book, "Physical Design of Yagi Antennas." Clearly, you are not designing a Yagi, but a lot of the material strength, deflection, wind loading, etc is applicable. There was also an Excel workbook offered by ARRL to accompany the book. I have it someplace, but can't lay my hand on it at the moment. Once you get the above ground part designed, you need to worry about the anchor too. Here's a link to a paper that might help the http://k6mhe.com/n7ws/SizeConcrete.doc Wes Sometimes it is best to back into the correct answer... The suppliers are going to charge me for 5 yards of concrete in my area whether I use it or not... The other choice is to mix it myself. John Ferrell W8CCW "Life is easier if you learn to plow around the stumps" You might want to see if you can rent a 1 yard cement delivery trailer. Some tool rentals have them. Dave N |
Tower design
John Ferrell wrote in
: The other choice is to mix it myself. What is the strength of "mix it yourself" concrete? You might need the five yards! Down here, "mix it yourself" costs more than readymix (provided you are near a readymix plant), and if you "measure" the mix with a shovel, it will be rated lower in strength. If you mix it in a barrow, even worse. Owen |
Tower design
wrote in message ... I am trying to find information on build your own tower.... "Design Data for Pipe Masts", Ham Radio, July 1989, pp. 38 ff. "A One-Man Skyhook", QST, July 1947 pp. 19 ff. "A Sturdy 55-Ft. Skyhook", QST, October 1947, pp. 28 ff. "A Low-Cost Tilt-Over Tower", QST, November 1971, pp. 22 ff. "A 40 Foot Non-Conductive Sky-Hook", 73 Magazine, July 1968, pp. 16 ff. "Telescoping Antenna Mast", QST, March 1958, pp. 28 ff. "The Beam Pole", 73 Magazine, date not on torn-out article, pp. 24 ff. "A Self Supporting Antenna Mast", CQ, November 1962, pp. 44 ff. "A Foldover Cheapie", 73 Amateur Radio, September 1987, pp. 19 ff. "New Approach to the Fold-Over Tower", QST, date unknown, p. 36 "A Tilt-Over/Swivel Antenna Mount for Recreation Vehicles", 73 Amateur Radio Today, July 1993, pp. 28 ff. "A Self-Supporting Antenna Tower", QST, March 1941, pp. 18 ff. "A Counterweighted Antenna Tower", Radio, November 1941, pp. 44 ff. "Sixty Cents Per Foot", QST, June 1959, pp. 30 ff. "Lightweight Utility Mast", QST, July 1960, pp. 30 ff. "A Telescoping Mast, Mark II", WST, April 1966, pp. 96 ff. -- --Myron A. Calhoun; W0PBV; 2001 Dunbar Road; Manhattan, KS 66502-3907 Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge NRA Life Member & Certified Instructor for Rifle, Pistol, & Home Firearm Safety Also Certified Instructor for the Kansas Concealed-Carry Handgun (CCH) license Thanks a million I have been looking for an excuse to get back issues of QST on a disk. Jimmie |
Tower design
On 16 Mar, 14:45, Owen Duffy wrote:
John Ferrell wrote : The other choice is to mix it myself. What is the strength of "mix it yourself" concrete? You might need the five yards! Down here, "mix it yourself" costs more than readymix (provided you are near a readymix plant), and if you "measure" the mix with a shovel, it will be rated lower in strength. If you mix it in a barrow, even worse. Owen And what would it fail by if mix was rated lower in strength, presumably it would have steel reinforcement? I would have thought the tower itself would be the weakest link. Art |
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