Just as I am getting ready to put my windom up the article below came from Amateur Radio.com. I may still have to put up a pulley and weight as I am raising a full 160 meter windom and the longer leg will be 182 feet long. That will be a lot of wire hung in the air. This is the one I am putting up…
A Shock-Absorber for a Wire Antenna
21 October 2011 | by Todd NØIP | Share | | Leave a Comment (1)
Of the three support-points for my wire antenna, one of them has caused me some concern. The end of the longest span of my New Carolina Windom is attached to a rigid, unguyed 12 foot steel mast by a very short length of rope — not nearly long enough to stretch and absorb the shock that a wind-whipped wire might induce in a good storm. Furthermore, this 12 foot mast is set in a small 3? tripod without any reinforcement below the roof. Obviously this isn’t good enough for a heavy load, but I’m hoping it will suffice to support one end of a 42? wire. As a precaution, I’ve built a shock-absorber into the system:
This is a spring that I bought at the local hardware store. I didn’t do any calculations to select the thing. I just went through the drawers and handled all the likely-looking springs they had. This one felt about right when I pulled on it. I tied it into the 3/32? braided dacron/nylon rope with a loop long enough to match the length of the spring when fully extended. The electrical tape is to prevent chafing for as long as it stays on.
The spring is strong enough that on a calm day it doesn’t stretch at all, but it still has plenty of give if the wire gets to whipping around. Will it help this antenna-system weather the storms we get out here in western Minnesota? Time will tell!
Todd Mitchell, NØIP, is a regular contributor to AmateurRadio.com and writes from Minnesota, USA. He can be contacted at lamentans@gmail.com.
One Response to “A Shock-Absorber for a Wire Antenna”
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Fred W0FMS:
Except for the fact that those types of springs turn rusty ugly fast, they work for years. I find them to be much more servicable than a pulley and weight which is usually suggested for this use. Spring steel surface rusts fast but then doesn’t get worse for a long time.
Of course, in my case, it still doesn’t prevent a tree falling throught the path of the antenna from taking it down! (I am starting to hate wire antennas)
Fred W0FMS