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Message |
    
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 109
Registered: 7-2004
| | Posted on Sunday, August 08, 2004 - 7:19 pm: | 
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I Live in an area where the winds get up to 40mph or so, and on the rare occasion maybe 60mph. But that is very rare. I was wondering how many feet of free standing mast pipe I could get away with using the I-Max 2000.
Any help would be greatly appreciated.
Thanks in advance
Bob |
Yankee
Intermediate Member
Username: Yankee
Post Number: 194
Registered: 7-2003
| | Posted on Sunday, August 08, 2004 - 9:43 pm: |
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Hi Bob, Here in Oklahoma at times we get 85 MPH flat winds, that can and do amount to a lot of antenna damage. With my QTH being on a hill, it sometimes gets bad here. My mast is an almost 16 foot piece of heavy gauge steel chain link fence pipe, 1 and 3/4 inch OD. It is free standing with the heavy gauge 15 inch South River Wall mounts mounted on my porch railing and I wouldn't think of even going any higher than the overall height of 39 feet 6 inches that my I MAX2000 is at.
73, Carl CEF-357 |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 112
Registered: 7-2004
| | Posted on Sunday, August 08, 2004 - 11:36 pm: |
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Thanks Carl What I am going to do is run standard unpainted mast pie up along the house to the second story eve's and attatch metal plumpers tape in two places to hold it against the house. But was wondering how high above the eve's I could get. I'm guessing about 10 maybe 14 feet above the eve's would be about the max then?
Thanks for the response
Bob |
Pig040
Advanced Member
Username: Pig040
Post Number: 537
Registered: 7-2003
| | Posted on Monday, August 09, 2004 - 9:50 am: |
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Bob,
The rule of thumb that I have always heard is after 10 feet, used guide wires. I know other peope that have gone a lot farther and got lucky, but I also know a guy that had 20ft of mast above his roof unguyed, and it aquired a 90 degree bend! I had 40 ft on a pushup pole running up a tree, unguyed, and it lasted a week or so!!
RIch |
Yankee
Intermediate Member
Username: Yankee
Post Number: 196
Registered: 7-2003
| | Posted on Monday, August 09, 2004 - 11:22 am: |
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Hi Bob, That plumbers steel straping is one thing that would not work here in Oklahoma, It wouldn't take much of a wind to put the whole thing on the ground. You have stated that you do get 40 MPH winds. Winds like that would tell me to mount my antenna with the heavy duty South River no less than 15 inch wall mounts and also drive an 8 foot copper ground rod and also ground my whole station. And yes, No more than 10 feet above the house free standing. Also as Rich has said trees are a No No. 73,Carl CEF-357 |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 116
Registered: 7-2004
| | Posted on Monday, August 09, 2004 - 1:16 pm: |
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Thanks Rich I guess I will take it down a few feet then. Right now thats where the Antron 99 sits, and it's been ok for the last couple of years. But the I-Max is bigger and no need to push it. I hate dropping below 36 feet tho. I had it about 19 feet above the eve, and it runs up into the tree. From what I understand I should make sure the radiator doesn't touch the trees is that right? |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 117
Registered: 7-2004
| | Posted on Monday, August 09, 2004 - 1:45 pm: |
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HI Carl well we get gusts up that high never sustained winds, but the way the antenna is mounted the winds blow against the side of the house the antenna's are mounted, and the house gives support to the whole set up. But again the I-Max is 6 feet taller and I don't want to take any chances that's why I asked.
About the ground pole. it's impossible. The mountain I live on is made of granite and if I'm lucky it might have 3 feet of soil over the rock. The last pipe I drove in the ground was for the station equipment it was 3 and 1/2 feet and at about 2 and 3/4 feet the heavey duty copper tubing broke at the top. I was using a 3 pound sledge, and it kept bouncing off of the top of the tubing .The top of the pipe was pretty flat by then then and it began to turn slightly. I straightened it out a little and then it just broke off. And this was after soaking the ground to make it easier to drive in.
I guess what I'm trying to say is up here in the California mountains at 7200 feet we really don't have anywhere near 8 foot of top soil, just a light cover of rocky dirt then granite. |
Yankee
Intermediate Member
Username: Yankee
Post Number: 198
Registered: 7-2003
| | Posted on Monday, August 09, 2004 - 8:01 pm: |
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Dream on Carl, what I couldn't do at 7200 feet. I could set the antenna on a tripod with 5 feet of mast on the ground. At 7200 feet you don't have to worry about mast, plus granite underneath the top soil. Back home in upstate New York I lived on a limestone ledge that did wonders for my PDL II at 72 feet to the feed point. My location back home was a skip shooters dream.
73, Carl CEF-357 |
Crackerjack
Intermediate Member
Username: Crackerjack
Post Number: 228
Registered: 7-2004
| | Posted on Monday, August 09, 2004 - 9:52 pm: |
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I would think that 7200 feet, a long wire or inverted V would be a great antenna.
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Bob_p
Intermediate Member
Username: Bob_p
Post Number: 120
Registered: 7-2004
| | Posted on Tuesday, August 10, 2004 - 12:50 am: |
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Right now I have a 2 meter antenna on top of the second story with 15 feet of mast. I think I will just take the 2 meter antennna down take off the 5 foot section so there is 1 10 foot section and put it up on that. It would be nice if I could have the other 5 foot section on it to get it to 35 feet, but I guess it won't make that much difference.
Thanks for all of the response guys I appreciate the help. But I can live without a 2 meter antenna at feet. |
Tech808
Moderator
Username: Tech808
Post Number: 3258
Registered: 8-2002
| | Posted on Tuesday, August 10, 2004 - 1:10 am: |
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Bob_p,
Just a suggestion here.
Get 2" Mast pipe and 1 3/4" mast pipe and insert the 1 3/4 inside the 2" for re-inforcement.
Or like I did on my tower at the 10' top section sticking above the tower for my beams I used 2 1/2" Mast pipe and reinforced it by inserting / Pounding 2 1/4" Black Gas Pipe inside.
Very Heavy but no worry about bending. Poor Homeboy and Redman liked to died hauling it up to the top of the tower. 
Lon
Tech808 |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 121
Registered: 7-2004
| | Posted on Tuesday, August 10, 2004 - 2:10 am: |
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Thanks for the suggestion Lon at least this is just 10 feet on a tri-pod on the center of the second story. I have a ten foot section of heavey galvenized steel but it's something like 1". I would think that would do, tell me if I'm wrong. Anyway getting up to that second story would be a challenge for me so I'm going to have to hire someone to do it. If I was 30 again oh well...
Thanks again
Bob |
Yankee
Intermediate Member
Username: Yankee
Post Number: 199
Registered: 7-2003
| | Posted on Tuesday, August 10, 2004 - 12:20 pm: |
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Hi Lon, I take it your tower isn't a tilt over with a dead man and a yoke to set the top in when you bring it down to work on the rotor or beam. That's the way most of the boys with high towers here have their towers set up. With this set up one person can put a tower up or down. One of my buddies 30 miles north of me is at 72 feet to the boom of his Moonraker 4 with this rigging on his tower.
Carl CEF-357 |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 124
Registered: 7-2004
| | Posted on Tuesday, August 10, 2004 - 1:29 pm: |
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I do have to wonder if that extra 5 foot section would make any diffence though. I know I'm at 7200 feet, but what about the 36 foot full wave length rule?
Thanks again
Bob |
