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attaching guy ropes to a trap vertical antenna
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by K8VPL on May 1, 2006
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Hello everyone. ..looking for ideas here....I am planning to install a roof mounted vertical antenna, a 4BTV, and am looking for some guy rope attachment ideas. The recommendation is attaching 3 or 4 guy ropes (proper materials of course, UV stabilized) to a point just above the 20 meter trap. The specific question: I don't want to just tie the end of the guys into a "lump" of four knots above the 20 meter trap. Has anyone thought of and used a "better" method? I was thinking of forming some kind of loop at the end of each rope to slip over the tubing. Or, I wondered about making a plastic (or whatever material) disk with a big hole in the middle and slip that on to the tubing, and drilling 4 holes through the edge to attach the rope ends. But, again, I want to avoid just plain old tying knots (which I fear may come loose). Anchoring the far ends is not the problem....attaching it to the antenna is where I am looking for ideas. I'm spoiled because I have spent a career working on tall broadcast towers, but I have yet to see anything scaled down to a small piece of tubing on a roof. Anyone have any tested or untested suggestions? Thanks.
Ted K8VPL
AMFMTV@AOL.com
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RE: attaching guy ropes to a trap vertical antenna
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by WB6BYU on May 1, 2006
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Ted -
Not sure what your picture of what sort of knots you would
be using, but a "lump of knots" isn't how I would imagine
it turning out. Each rope only has to go once around the
antenna, so you could tie a loop in the end of each rope
and slip them over the end of the vertical. (You want the
loop to be larger than the radiator but smaller than the
diameter of the trap.) Given that the required rope is
actually fairly small, this shouldn't be unsightly.
The loops could, of course, be tied directly around the
antenna rather than slipped over the end (which would be
inconvenient if it has a capacity hat.) I'd probably try
something like making two loops out of short lengths of
rope and tying each in a clove hitch just above the trap.
(This actually would make more of a "lump" than the other
method.) Each of these would then have two ends sticking
out, each of which was actually a loop of rope that the
guys could tie to with a slippery sheet bend. You can
accomplish the same thing by tying four small loops and
passing a single turn through all of them and around the
mast. This would give you one rope going around the mast
with 4 loops through it to tie the guy ropes to.
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RE: attaching guy ropes to a trap vertical antenna
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by WB2WIK on May 1, 2006
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I don't tie guy ropes directly to vertical antennas, at all. I use a mast clamp and tie the ropes to that.
A mast clamp is a three-part forged plated steel assembly that surrounds the mast (or in this case, the antenna radiator) and provides eyebolts, tightened with nuts and lockwashers, used for tying guy ropes. It's held together by the eyebolts themselves, making the assembly adjustable to accommodate different mast sizes from small (about an inch) to large (about two inches), just by unthreading or tightening the nuts on the eyebolts.
They're usually plated or galvanized steel and will last a long time without rusting. They cost about $2-$3 each, and last time I looked, Home Depot had them in their electrical department, near the TV antennas, masts and miscellaneous antenna hardware.
Tighten one of those to your antenna at the appropriate spot, and tie the ropes to the eyes of the eyebolts. I use ordinary double braided Dacron rope, and ordinary knots hold it forever. Burn the end of each rope to seal it, which also makes it swell in size so it cannot possibly slip back through the knot, and you're done.
I guyed by 6BTV like this in about two minutes. It's been up for years, through 75+ mph winds.
WB2WIK/6
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RE: attaching guy ropes to a trap vertical antenna
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by K5LXP on May 1, 2006
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It probably could be pointed out too that 'rope' is a bit of overkill. I've guyed antennas like this with mason's twine. A vertical like that doesn't have a lot of square footage, so even light twine is up to the task. Dacron has the advantage of being more resistant to UV but I've had mason's twine last for years even here in NM.
Mark K5LXP
Albuquerque, NM
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RE: attaching guy ropes to a trap vertical antenna
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by N3BIF on May 2, 2006
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I too use the masons twine, however I run it from the ground though the eye bolt and back to ground, this allows it to be
double the strength
no inaccessible knots
ans should the line show signs of wear I can replace it without leaving the ground , just attach new to old and pull the old through until the new has been replaced. If you want you can do this periodically to inspect for wear or even replace just as a matter of routine.
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RE: attaching guy ropes to a trap vertical antenna
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by K8VPL on May 2, 2006
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Thanks, gentlemen, for the replies and answers. Its given me several new ideas, and I appreciate the insights.
Ted
K8VPL
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RE: attaching guy ropes to a trap vertical antenna
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by KB9CRY on May 3, 2006
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And I believe you'll not be needing to "guy" that vertical like you'd guy a tower. For my HF2V I use 3/32 UV resistant Dacron cord (CableXperts) and just each once around the vertical section and secure it with a bow-line knot. I then loosely tension the cords so that they all just prevent the antenna from whipping back and forth in high gusty winds; they just let the antenna "lean" over a bit. These cords (similar to parachute cord) are rated at around 200# tensile strength which is more than sufficient. Mine have been up 5 years now with no issues.
Phil
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RE: attaching guy ropes to a trap vertical antenna
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by W5GA on May 3, 2006
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If you tie real knots (as opposed to "granny" knots) they will hold until the cows come home. They can also be untied with little effort when the time comes. I have a 1/4 wave 40m GP on my roof, guyed with light nylon line. I used bowlines at the antenna to form the loops, and taught line hitches at the roof end to allow tension adjustment. See any Boy Scout handbook for instructions on how to tie real knots that will hold, and can be untied at will without a knife.
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RE: attaching guy ropes to a trap vertical antenna
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by W5GA on May 3, 2006
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If you tie real knots (as opposed to "granny" knots) they will hold until the cows come home. They can also be untied with little effort when the time comes. I have a 1/4 wave 40m GP on my roof, guyed with light nylon line. I used bowlines at the antenna to form the loops, and taught line hitches at the roof end to allow tension adjustment. See any Boy Scout handbook for instructions on how to tie real knots that will hold, and can be untied at will without a knife. This has held fine in up to 60 mph. winds.
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RE: attaching guy ropes to a trap vertical antenna
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by KA0GKT on May 6, 2006
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I suggest a Bowline. At the anchor points, a Taught-Line-Hitch allows for adjustment of tension, however a sheep-shank will let you put slack into the line quickly if necessary.
I have seen the umbiquitous clove-hitch used, but on slick aluminum antenna elements, I'm not too sure it will work without the addition of a square-knot.
Find an old Boy Scout Handbook.
73 DE KAØGKT/7
--Steve
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