Antenna "Rope Fuse" Material?

[W1AEX]

After losing all my wire antennas several times last winter and again in the nasty storm at the end of October, an idea that was mentioned to me while chatting with Joe WA3WMI on 40 meters is starting to make a lot of sense. Joe suggested that there should be a built-in "weak link" that would allow the wire antenna to break away when a tree or limb falls across it. Since I do employ pull down ropes at the end insulators so the rope ends never get caught up in the tree, this would be really easy to install and would make recovering the antenna after an "event" a one minute chore rather than a project.

The question I have is what material might lend itself to serve this purpose? It would need to be strong enough to hold up the antenna at each end while being resistant to the usual UV and outdoor exposure conditions. I was thinking maybe heavy duty fish line, but I don't think it likes UV exposure. Any thoughts?

Rob W1AEX

[The Slab Bacon]

Dacron rope. It's just about impervious to UV damage. Also be sure to put a pulley on one side of the antenner with a floating weight .

Mine is still up with the same dacron rope after 15 years! ! !

[KA2DZT]

Frank,

Why don't you read the question before you answer.

He wants to know what he should use for a fuse link.  Something that will break before any other rope breaks.

I've used 40# fishing line, not a good idea.

Just use some lighter weight rope or string for your breakable link.

Some of my antennas are set up that way.

Fred

[WA1GFZ]

nylon Mason's string rated at 200 pounds. Could use it as a tie on the ground connected to support rope.
My reference dipole in the woods. Dual #10 twisted didn't break with a large limb hanging on it. 5/16 dacron rope held it up. Lowered it yesterday and removed the limb and pulled it back up. been up over 20 years.

[The Slab Bacon]

Fred,
        Just like when you are on the air................... You missed my point.

My point was that if he used a pulley and a bob weight instead of tying it off solid and fast he might not have to use a "fuse".

Duhhhhhh..........................    

Just FWIW, last year we had a nasty ice storm here. The Wires were close to 3" in diameter with ice! My antenner was down so low that you could reach up and touch the center dogbone. The bob weight was up near the top of the pole. The next day after it warmed up a bit and the ice melted, it was back up where it started. All automatic, you dont even have to think about it, it does it all by itself.  

[KA2DZT]

Slab

OK OK

I saw your point, but couldn't pass up a chance to break your chops.

Fred

[Jim, W5JO]

I use binder twine for my "fuse'.

[W2PFY]

I use a wad of chewing gum in the winter, bubble gum in the summer!

[Bill, KD0HG]

This is a crazy one, but it works in rodeos, anyway.

Breakaway roping is a type of calf roping where a calf is roped, but not thrown and tied. Once the rope is around the calf's neck, the roper signals the horse to stop suddenly. The rope is tied to the saddle with a rope breakaway.. When the calf hits the end of the rope, the rope is pulled tight and pulls apart. Contestants are judged by how much time elapses between when the calf is released from a chute until the breakaway releases. They sometimes tie a red flag on the breakaway to make it easier to see when it breaks apart.

http://www.smithbrothers.com/double-s-barrel-breakaway/p/X3-11635/
http://www.rodeohard.com/Double-Barrel-Breakaway_p_1559.html

There are other brands and types of rope breakaways.

This is exactly the function that you're looking for.

Bill

[W1AEX]

Thanks for the ideas and the humor too. As the thread indicates, there's more than one way to handle this. The simplicity of using binder twine as suggested by Jim (W5JO) or string as Fred (DZT) mentioned, is quick and easy and makes that the first thing I will try. Bill (KD0HG) the "breakaway" used in calf roping looks perfect for this application. I may migrate to that solution at some point and thanks for passing it along! Frank, the pulley system would work fine, but as I get closer to full blown old buzzard status I'm moving toward making everything simpler. Not that pulleys are complicated, but a "breakaway" solution is much simpler.

My biggest concern here is that in the past the stress of a broken tree or heavy limb falling across my wire antennas has resulted in damage to my "favorite" high limbs that I use for supports. In fact, one event ripped the top 10 feet of a pine tree right off the tree. Wire antennas are easy to make strong and can be repaired if needed but you can't put good tie-off limbs back up when they are ripped down!

Incidentally, yesterday I did find my missing fan dipole that was obliterated when the top of a tree fell across it. The dipole was very sturdily constructed of #12 wire, which did not break. The entire antenna sling-shotted itself over the 80 foot oak it was tied to when the porcelain insulator at the far end broke in half. It now resides (nearly invisibly) on the crown of the oak tree.

Thanks for the "breakaway" ideas!

Rob W1AEX

[KA2DZT]

That fan dipole at the crown of the oak tree should improve reception.

Just thought I'd mention it.

Fred

[W7TFO]

What is an Oak tree?

Just kidding.

We string wire from Saguaro to Saguaro for antennas, with a Green Mojave rattlesnake tied into the pull rope for a 'fuse' for those Haboob winds. 

Keeps the saboteurs away, too.

O-n-O from the land of cact-ass.

DG

[WA1LGQ]

Rob, I am going to attempt the re-installation of my dipole that came down in the Halloween hellstorm. I have finally finished most of the tree branch cleanup and roof repair.  Now I get to deal with the leaves. I miss my antennae. The discone came down too, so no 6M FM from here until whenever. The dipole is going back up with new wire and regular 3/8" rope on one end and the other end will be at least for now some wimpy looking nylon cord. The stuff seems pretty strong, but you got me thinking, so I will try this. Normally I would use this kind of cord for the intermediate stage of antenna wire erection, next step would be to go to the final full strap nylon rope. So lets see what goes first next time a limb falls from the sky or what. ........Larry