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Old December 6th 10, 07:21 PM posted to rec.radio.amateur.antenna
jerry jerry is offline
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First recorded activity by RadioBanter: Dec 2010
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Default Rigid, unguyed dipole end supports?

On Mon, 06 Dec 2010 14:23:46 +0000, Bert Hyman wrote:

The size and layout of our city lot means that I can fit a 40 meter
dipole in the back yard with one end supported at the peak of the roof,
but with no way to guy a mast to hold up the other end. Power lines run
directly along the property line in back, there electrical service line
runs right across the roof of the detached garage and there are no trees
back there.

I picked up a couple of [cheap] 10' steel mast sections at the local
Radio Shack and attached the lower section to our fence with conduit
clamps, but just the weight of the antenna under minimum tension causes
the upper section to bow significantly.

I'd like to replace the far-end support with something that will stay
erect under tension without guys. Getting higher than 20' would be nice
too.

Can anybody offer practical suggestions to someone with essentially no
mechanical skills, pointers to articles on the subject or commercial
products?


I set up an 80m dipole using three masts made of 20 foot long 2x4's from
the lumberyard. I don't use any guy ropes, even on the end masts. I just
made diagonal braces from shorter 2x4's -- about 6-8 feet each -- with
two braces on each vertical mast.

The braces are attached to the mast with carriage bolts and one long lag
screw for the brace that attaches to the narrow edge of the mast. The
braces are arranged at 90 degree angles to each other and are dug into
the ground about 1 to 2 feet deep (that's all I can dig in this yard
before hitting hardpan). Each brace has a short "deadman" stick screwed
on the bottom of it to keep it from pulling out of the dirt.

There is also a vertical brace dug into the dirt and rising about 3 feet
above ground line. The actual mast is lapped onto the vertical brace with
two carriage bolts. The purpose of the vertical brace is mostly to get
the maximum rise out of the 20 foot mast. You could also just bury the
end of the mast itself into the dirt.

It's been up for a year now and hasn't come down even in the wind storms
and ice storms we have had. Be sure and orient the 2x4 mast so the
"strong" direction is opposed to the weight of the antenna.