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#11
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Bill:
You need to enlist a little geometry and mechanical engineering. We like to keep our top guys at 45 degrees or less (ground up to guy) where space permits. The down force on the mast for each guy is then .707 of the guy tension. As the guys get steeper, the down force on the mast becomes a larger and larger portion of the total tension. So for a smaller 'footprint' with the guys near straight up, any side force on the guy from wind or antenna tension becomes a larger down force on the mast. I need to make drawings to clarify that point, so find someone mechanically inclined to wave their hands and draw lines and make calculations for you. As far as the stepladder on the roof, consider the average male is just under 6' tall, with an 18" up reach. So he has to stand only 4 feet above the mounting level of the base of the mast to erect it. A 5 foot stepladder straddling the peak of most roofs is relatively stable if you are young, limber and agile. Having the first (bottom) section SOLIDLY guyed is a must. At least that's what I remember from the middle of the last century. -- Crazy George Remove N O and S P A M imbedded in return address "zeno" wrote in message ... Hi John, For a 50' tall mast, what would you say would be the minimum acceptible square dimensions from vertices (on a flat plane with the base) of the guy wire anchor points? Bill K6TAJ John Moriarity wrote: "zeno" wrote in message ... How the heck did those TV crews of yesteryear erect 40+ foot telescoping antenna masts sitting atop pointed roofs? Its not exactly like you can set up a step ladder on such a roof to get up the first 10 foot to pull up the rest of the sections. That's exactly what we did! When you are young and fearless and believe in your personal immortality, it's amazing what you can do ;-) 73, John - K6QQ |
#12
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Hi Bill
After a serious fall a number of years ago, I am now terrified of heights like you wouldn't believe. Yet I am still able to put up 50 foot towers, push-ups and even sectional guyed poles by myself with no problems. On push-up poles, I lay them on the ground first, open them up, make point to point guy ring measurements, mark the poles for their maximum safe expansion and close the assembly back up and haul it up to the roof. The main body is guyed and finished off prior to doing anything else. Using the formula to find the hypoteneuse the guys are marked for full length, then remarked for each lifting stage of the operation. The antenna or antennas are affixed to the innermost or highest part of the mast, which is only extended at this time long enough to do this operation. The ladder to reach them is set on the roof and tied to the now rigid base mast section. Before lifting, the guys for section one are clamped at their first set of markings, which allows a little slack or you couldn't lift it to the proper fixed height. After the clamps are in place, as you lift the first section, the guys slide through the eyes until they near the clamp. The mast is only lifted about 2 feet at a time and the standoffs for the ladder line are installed or the coax affixed to the mast with ties. Again it is lifted another 2 feet and a standoff or tie or both are installed. Repeated until you reach your 10 foot marking and this top section is then locked down solid. Now clamps are installed to the guys for section two to the first marking, the clamps for section one are loosened and clamps installed on the second marking for the upper guys. Here is where it helps to have 3 or 4 extra helpers to feed guys and keep them fairly taught. But if you don't have them, the pole is not going to fall further than the next set of clamps on the guys, or about a 2 to 3 foot lean at this early stage, the lean gets less as the guys get longer. The second mast is pushed up, usually by bouncing it so the first clamps of the section one guys can slide on the cables but still have enough tension to hold the antenna upright for you. Again, working in 2 foot increments, the standoffs and/or ties are installed. By the time you get section two up to maximum height, you will not be able to lift the remaining sections by hand. It's not the weight, it's the tension on the guys and floating clamps that are your enemy. If your familiar with how a Pony clamp set works, I had a similar tool made for lifting push-pole sections. A clamp is affixed to pole two and to the main mast in two places. I simply turn the handle to lift the pole about 8 inches, then lock it down, crank the tool back down, let it catch the pole and unlock the mast and crank it up another 8 inches and repeat until I get to the two foot point. Then I install the standoffs and/or ties or both. Then repeat again. Once the whole assembly is at full height, the guys are then tensioned to their proper rating. If your guys are NOT equal distance from the tower, you will have to make adjustments to the tension settings to maintain a perfectly vertical pole. Many of your guys themselves can be used as antennas if you plan for this before setting up the system. I put up an 80 foot vertical single handedly using only 1 inch 10 foot sections of interconnecting pipes. We had intended going up 100 feet, but the pipe was not strong enough to hold itself without telescoping and splitting, so we halted at 80 feet. It stood for 9 years untouched and without problems. Taking it down was really simple. One hit to the lower pipe with a baseball bat and the whole thing came straight down on itself and finally stopped dropping at about 15 feet of height and leaned over, the antenna did not touch the ground and was salvagable. TTUL Gary |
#13
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I installed a Hy-Gain TH-3 Jr and an Alliance TV rotor on a 20 foot TV mast
on a 2 story house -- used a heavy duty antenna tripod for a base-- total height 42 feet. The drill was with 5 "Amateurs": 1. Under the roof -- installed 4 by 4's to take lag bolts from the Tripod base 2. Bolted down the tripod mount to roof and 4x4's -- under the roof added sealant to prevent water entering. 3. Raised collapsed TV mast with antenna rotor and 4 guy wires --secured in tripod 4. Guyed the 10 foot section with the 4 guy wires 5. Set step ladder next to 10 foot guyed section -- secured ladder with rope to mast 6. Stong buddy also held ladder against mast 7. Tall guy (me) ascends ladder. Had rope around my waist in case I nose dived off of the ladder 8. Horsed the collapsed section with 4 more guy wires attached -- up to 20 feet - secured guy wires (Total 8 guy wires) 9. Fed all hands Pizza and beer. 10. Antenna stayed up there thru storms winds et al for 15 years before I moved. Your installation may vary -- this is just the way we did it -- but we were are not professional installers, so caveat installer. I take no responsibility for your installation. You should contact professional TV antenna installers for their approval -- or better yet -- let them install it. -- deje a lector guardarse Amateur Radio is the best back-up communications system in the world, and that's the way it is. Walter Cronkite "John Moriarity" wrote in message ... How did you secure a step ladder on the peak of a roof? Well, If you're still somewhat chicken, you can enlist another person to foot the ladder ;-) 73, John - K6QQ |
#14
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Hi George,
A 45 degree angled guy from the top of a 50' tall mast will be out 50' from the base of the mast. That would suggest that the "square" made from the four anchor points is 100' on a side. I will have to look at the site and see if that is possible. Bill Crazy George wrote: Bill: You need to enlist a little geometry and mechanical engineering. We like to keep our top guys at 45 degrees or less (ground up to guy) where space permits. The down force on the mast for each guy is then .707 of the guy tension. As the guys get steeper, the down force on the mast becomes a larger and larger portion of the total tension. So for a smaller 'footprint' with the guys near straight up, any side force on the guy from wind or antenna tension becomes a larger down force on the mast. I need to make drawings to clarify that point, so find someone mechanically inclined to wave their hands and draw lines and make calculations for you. As far as the stepladder on the roof, consider the average male is just under 6' tall, with an 18" up reach. So he has to stand only 4 feet above the mounting level of the base of the mast to erect it. A 5 foot stepladder straddling the peak of most roofs is relatively stable if you are young, limber and agile. Having the first (bottom) section SOLIDLY guyed is a must. At least that's what I remember from the middle of the last century. -- Crazy George Remove N O and S P A M imbedded in return address "zeno" wrote in message ... Hi John, For a 50' tall mast, what would you say would be the minimum acceptible square dimensions from vertices (on a flat plane with the base) of the guy wire anchor points? Bill K6TAJ John Moriarity wrote: "zeno" wrote in message ... How the heck did those TV crews of yesteryear erect 40+ foot telescoping antenna masts sitting atop pointed roofs? Its not exactly like you can set up a step ladder on such a roof to get up the first 10 foot to pull up the rest of the sections. That's exactly what we did! When you are young and fearless and believe in your personal immortality, it's amazing what you can do ;-) 73, John - K6QQ |
#15
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Hi Gary,
Thanks for the thorough instructions. I am not sure I understand the pony clamp, but I agree that I can see a problem trying to lift up the combined weight of the last 4 of the 5 sections after the first 10 foot section is in place. Where can I see an image of such a "pony clamp"? I have two people trying to pull it up maybe it can be done by hand. Bill "Gary V. Deutschmann, Sr." wrote: Hi Bill After a serious fall a number of years ago, I am now terrified of heights like you wouldn't believe. Yet I am still able to put up 50 foot towers, push-ups and even sectional guyed poles by myself with no problems. On push-up poles, I lay them on the ground first, open them up, make point to point guy ring measurements, mark the poles for their maximum safe expansion and close the assembly back up and haul it up to the roof. The main body is guyed and finished off prior to doing anything else. Using the formula to find the hypoteneuse the guys are marked for full length, then remarked for each lifting stage of the operation. The antenna or antennas are affixed to the innermost or highest part of the mast, which is only extended at this time long enough to do this operation. The ladder to reach them is set on the roof and tied to the now rigid base mast section. Before lifting, the guys for section one are clamped at their first set of markings, which allows a little slack or you couldn't lift it to the proper fixed height. After the clamps are in place, as you lift the first section, the guys slide through the eyes until they near the clamp. The mast is only lifted about 2 feet at a time and the standoffs for the ladder line are installed or the coax affixed to the mast with ties. Again it is lifted another 2 feet and a standoff or tie or both are installed. Repeated until you reach your 10 foot marking and this top section is then locked down solid. Now clamps are installed to the guys for section two to the first marking, the clamps for section one are loosened and clamps installed on the second marking for the upper guys. Here is where it helps to have 3 or 4 extra helpers to feed guys and keep them fairly taught. But if you don't have them, the pole is not going to fall further than the next set of clamps on the guys, or about a 2 to 3 foot lean at this early stage, the lean gets less as the guys get longer. The second mast is pushed up, usually by bouncing it so the first clamps of the section one guys can slide on the cables but still have enough tension to hold the antenna upright for you. Again, working in 2 foot increments, the standoffs and/or ties are installed. By the time you get section two up to maximum height, you will not be able to lift the remaining sections by hand. It's not the weight, it's the tension on the guys and floating clamps that are your enemy. If your familiar with how a Pony clamp set works, I had a similar tool made for lifting push-pole sections. A clamp is affixed to pole two and to the main mast in two places. I simply turn the handle to lift the pole about 8 inches, then lock it down, crank the tool back down, let it catch the pole and unlock the mast and crank it up another 8 inches and repeat until I get to the two foot point. Then I install the standoffs and/or ties or both. Then repeat again. Once the whole assembly is at full height, the guys are then tensioned to their proper rating. If your guys are NOT equal distance from the tower, you will have to make adjustments to the tension settings to maintain a perfectly vertical pole. Many of your guys themselves can be used as antennas if you plan for this before setting up the system. I put up an 80 foot vertical single handedly using only 1 inch 10 foot sections of interconnecting pipes. We had intended going up 100 feet, but the pipe was not strong enough to hold itself without telescoping and splitting, so we halted at 80 feet. It stood for 9 years untouched and without problems. Taking it down was really simple. One hit to the lower pipe with a baseball bat and the whole thing came straight down on itself and finally stopped dropping at about 15 feet of height and leaned over, the antenna did not touch the ground and was salvagable. TTUL Gary |
#16
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Only three guys are needed. Your 100 foot number may be in error.
How about 75 feet between anchors in a three guy wire system? zeno wrote: Hi George, A 45 degree angled guy from the top of a 50' tall mast will be out 50' from the base of the mast. That would suggest that the "square" made from the four anchor points is 100' on a side. I will have to look at the site and see if that is possible. Bill Crazy George wrote: Bill: You need to enlist a little geometry and mechanical engineering. We like to keep our top guys at 45 degrees or less (ground up to guy) where space permits. The down force on the mast for each guy is then .707 of the guy tension. As the guys get steeper, the down force on the mast becomes a larger and larger portion of the total tension. So for a smaller 'footprint' with the guys near straight up, any side force on the guy from wind or antenna tension becomes a larger down force on the mast. I need to make drawings to clarify that point, so find someone mechanically inclined to wave their hands and draw lines and make calculations for you. As far as the stepladder on the roof, consider the average male is just under 6' tall, with an 18" up reach. So he has to stand only 4 feet above the mounting level of the base of the mast to erect it. A 5 foot stepladder straddling the peak of most roofs is relatively stable if you are young, limber and agile. Having the first (bottom) section SOLIDLY guyed is a must. At least that's what I remember from the middle of the last century. -- Crazy George Remove N O and S P A M imbedded in return address "zeno" wrote in message ... Hi John, For a 50' tall mast, what would you say would be the minimum acceptible square dimensions from vertices (on a flat plane with the base) of the guy wire anchor points? Bill K6TAJ John Moriarity wrote: "zeno" wrote in message ... How the heck did those TV crews of yesteryear erect 40+ foot telescoping antenna masts sitting atop pointed roofs? Its not exactly like you can set up a step ladder on such a roof to get up the first 10 foot to pull up the rest of the sections. That's exactly what we did! When you are young and fearless and believe in your personal immortality, it's amazing what you can do ;-) 73, John - K6QQ |
#17
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![]() Dave Shrader wrote: Only three guys are needed. Your 100 foot number may be in error. 100 feet would be the correct number if it was a two guy wire system. Right? :-) 73, ac6xg How about 75 feet between anchors in a three guy wire system? zeno wrote: Hi George, A 45 degree angled guy from the top of a 50' tall mast will be out 50' from the base of the mast. That would suggest that the "square" made from the four anchor points is 100' on a side. I will have to look at the site and see if that is possible. Bill Crazy George wrote: Bill: You need to enlist a little geometry and mechanical engineering. We like to keep our top guys at 45 degrees or less (ground up to guy) where space permits. The down force on the mast for each guy is then .707 of the guy tension. As the guys get steeper, the down force on the mast becomes a larger and larger portion of the total tension. So for a smaller 'footprint' with the guys near straight up, any side force on the guy from wind or antenna tension becomes a larger down force on the mast. I need to make drawings to clarify that point, so find someone mechanically inclined to wave their hands and draw lines and make calculations for you. As far as the stepladder on the roof, consider the average male is just under 6' tall, with an 18" up reach. So he has to stand only 4 feet above the mounting level of the base of the mast to erect it. A 5 foot stepladder straddling the peak of most roofs is relatively stable if you are young, limber and agile. Having the first (bottom) section SOLIDLY guyed is a must. At least that's what I remember from the middle of the last century. -- Crazy George Remove N O and S P A M imbedded in return address "zeno" wrote in message ... Hi John, For a 50' tall mast, what would you say would be the minimum acceptible square dimensions from vertices (on a flat plane with the base) of the guy wire anchor points? Bill K6TAJ John Moriarity wrote: "zeno" wrote in message ... How the heck did those TV crews of yesteryear erect 40+ foot telescoping antenna masts sitting atop pointed roofs? Its not exactly like you can set up a step ladder on such a roof to get up the first 10 foot to pull up the rest of the sections. That's exactly what we did! When you are young and fearless and believe in your personal immortality, it's amazing what you can do ;-) 73, John - K6QQ |
#18
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With four guys the distance between any two 180 degree opposing guys will be 100' at
the base level. That is why I said that four guys at 45 degree angle at the top of a 50' mast will make a square at the four anchor points and that square at the base level is 100' on each side. I am thinking that 30 degrees at the top might be fine for my project in which case a smaller square. Bill - K6TAJ Jim Kelley wrote: Dave Shrader wrote: Only three guys are needed. Your 100 foot number may be in error. 100 feet would be the correct number if it was a two guy wire system. Right? :-) 73, ac6xg How about 75 feet between anchors in a three guy wire system? zeno wrote: Hi George, A 45 degree angled guy from the top of a 50' tall mast will be out 50' from the base of the mast. That would suggest that the "square" made from the four anchor points is 100' on a side. I will have to look at the site and see if that is possible. Bill Crazy George wrote: Bill: You need to enlist a little geometry and mechanical engineering. We like to keep our top guys at 45 degrees or less (ground up to guy) where space permits. The down force on the mast for each guy is then .707 of the guy tension. As the guys get steeper, the down force on the mast becomes a larger and larger portion of the total tension. So for a smaller 'footprint' with the guys near straight up, any side force on the guy from wind or antenna tension becomes a larger down force on the mast. I need to make drawings to clarify that point, so find someone mechanically inclined to wave their hands and draw lines and make calculations for you. As far as the stepladder on the roof, consider the average male is just under 6' tall, with an 18" up reach. So he has to stand only 4 feet above the mounting level of the base of the mast to erect it. A 5 foot stepladder straddling the peak of most roofs is relatively stable if you are young, limber and agile. Having the first (bottom) section SOLIDLY guyed is a must. At least that's what I remember from the middle of the last century. -- Crazy George Remove N O and S P A M imbedded in return address "zeno" wrote in message ... Hi John, For a 50' tall mast, what would you say would be the minimum acceptible square dimensions from vertices (on a flat plane with the base) of the guy wire anchor points? Bill K6TAJ John Moriarity wrote: "zeno" wrote in message ... How the heck did those TV crews of yesteryear erect 40+ foot telescoping antenna masts sitting atop pointed roofs? Its not exactly like you can set up a step ladder on such a roof to get up the first 10 foot to pull up the rest of the sections. That's exactly what we did! When you are young and fearless and believe in your personal immortality, it's amazing what you can do ;-) 73, John - K6QQ |
#19
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Jim Kelley wrote:
Dave Shrader wrote: Only three guys are needed. Your 100 foot number may be in error. 100 feet would be the correct number if it was a two guy wire system. Right? :-) 73, ac6xg Yep! And the guys would provide an unconditionally unstable system. |
#20
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Bill, that's correct. But, most guying systems are only 3 wires on a 120
degree spread at 45 degrees from the anchor on the tower/mast. That requires only 75 feet. A three wire system is a STABLE solution. A four wire system is also a stable system. BTW, I used to have a Rohn 25 system at 50 feet. Rohn recommended double guying. First level at the 30 foot height. Second level just below the rotator platform. Point I'm making is that one set of guys at the 50 foot level may not meet Zoning and Insurance safety requirements. Deacon Dave, W1MCE zeno wrote: With four guys the distance between any two 180 degree opposing guys will be 100' at the base level. That is why I said that four guys at 45 degree angle at the top of a 50' mast will make a square at the four anchor points and that square at the base level is 100' on each side. I am thinking that 30 degrees at the top might be fine for my project in which case a smaller square. Bill - K6TAJ |
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