[TowerTalk] Your Opinion on Rohn 45 and Monster SteppIR

Dennis O'Connor k8do at mailblocks.com
Mon Aug 29 08:51:44 EDT 2005


A 70' 45G is more than adequate for your MonstIR... Assuming it is properly guyed - The biggest issue is guying... 
I have a 120' and a 150' of 25G that is holding up more than 25 square feet (each) for 11 years now... My opinion is that it will last because it is properly guyed...  Spend your money on guy wire and anchors, not on thicker tower...  The strongest tower in the world will come down if the guys fail...  25G will withstand a hurricane if the guys do not fail... 

My guying schedule is:
First anchor is 60'  out from the tower and has the 30' and 60' guys attached...
Second anchor is 120 feet out and has the 90' and 120' guys attached...
Third anchor is 150' out and has the 150' guy attached...

No anchor is supporting more than 60 foot of tower... Notice that the top 30', with the 4 element 40 meter  beam, has it's own guy anchor (in effect it is holding up a 30' tower with a beam on it)...  Notice that the steepest guy is 45 degrees and it's mate is at 22.5 degrees...  This puts the majority of the tension on the guys into supporting the tower laterally and snubbing rotation, not in pulling down on the tower...

If you are very concerned about your 45G tower put 4 guys around it, of 4500 pound tensile strength, at three levels, 23' / 46' / 70'...  Use separate guy anchors for each level with the guys at 45 degrees or flatter... Set up like this it will withstand a hurricane (though I doubt the antenna will)....

denny


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