Count me firmly in the side that approves of guying a self supporting tower.
And I can personally attest to VE5RA Doug's experience with guyed Delhi
structures - he has been there and done it and they have survived..... with
significant loads such as 4 el 40m KLM's to well over 100 feet. And in
Canada what we refer to as the "Coke Bottle" style of Delhi (older stuff
with stepped transitions) appears very similar to Rohn BX.
Look at any Rohn tower book or spec - Rohn tower sections are self
supporting to "X" feet. Add guy wires and the structure is good to X plus
many more feet.
Multiband verticals are designed to be self supporting but many
manufacturers suggest guying to increase survivability.
People truss or "guy" the elements of 80m yagis all the time. Now there's a
long slender tapered structure. Sensible guying will certainly help it
survive.
Yes, guying a self supporting structure will change both the stresses and
eventually the mode of failure. However any such failures will occur at
higher - and I believe significantly higher - wind speeds.
73 Don
VE6JY
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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