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Author Topic: How to get a wire high up a tree - safely  (Read 2977 times)
PA3GMP
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Posts: 75




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« on: June 21, 2009, 08:07:57 AM »

Dear fellow hams,

Until recently I have spent my life at QTH's with little or no options for a decent HF antenna. Now, though, I live on a property large enough for a decent G5RV for 80m, or something similar. (I'm not necessarily going to use a G5RV; I merely mention it to illustrate sizes and dimensions.) I'd prefer not to use an inverted V, though.

There is no room to put up (a) tower(s); my landlord would probably not approve (I'm currently renting) and my budget doesn't allow for any of that either. Fortunately there are quite a few nice, high pine trees on the property. I want to suspend my wire from two of those.

However I'm not at my best on a ladder (I've got a bad sense of balance and I'm not very agile) and I've fallen out of a tree once already - fortunately from a moderate height and with no serious injuries). In short, I'm not too keen on climbing a 30 foot ladder standing against a pine tree.

Which leaves me with the question of how to get a pulley at least 10m (33ft) up a pine tree. The idea is to get a pulley up there so I can lower the antenna when necessary, and use weights to keep tension on the wire. I've tried to use a catapult to get some fishing line up there, but branches kept getting in the way, and getting the line (let alone the rope) around the tree proved a problem. I don't know anyone with a bow and arrow (or better, a crossbow).

Suggestions, anyone? All feedback would be appreciated!

73 Frank PA3GMP /ZS6TMV
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WB2WIK
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Posts: 20633




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« Reply #1 on: June 21, 2009, 09:28:56 AM »

I've put dozens of pulleys up in trees higher than that.

Start with very thin monofilament fishing line and a small weight tied to its end.  It's best if the weight is "rounded" and doesn't have any corners; I often use lead fishing sinkers, or even old (junk) sockets from a socket wrench set.  Anything "smooth" that won't get hung up in branches.

To get the starter line up over the tree, I've often used an inexpensive fishing rod and reel, and just "cast" the weighted line up and over.  Fishing line is really cheap and so are sinkers, so if some tries don't make it or get tangled up, just cut the line and cast another one.  Other methods such as slingshots work fine, too...but it's good to still leave the line on a reel so it can spool out smoothly without snagging on anything.  For this, you can just clamp the fishing reel to a convenient fence post or anything that's a few feet above ground and doesn't move.

It often takes some "jerking" of the line to get the sinker to fall back to the ground, but with practice, it will.

Once the weight is within reach or on the ground you now have a "pull line" for something larger, like rope.  Tie a rope onto where the sinker was (the thin nylon line) and "reel in" the fishing line to pull the rope up and over the tree limb.  You need enough rope to go from ground, up over the tree, and back to ground again.  To clear a 30' tree, you'd need at least 80-90 feet of rope.

Once both ends of rope are on the ground and the rope is over the tree limb, tie a pulley on to one end of the rope.  Run your ultimate "hoist line" through the pulley and make sure the rope is long enough to also reach from ground to ground once the pulley is up at the tree limb level.  So again, for a 30' tree, I'd plan on 80-90 feet of rope, minimum.

Use the first rope to pull the pulley up into the tree until it hits or is close to the high limb.  Tie off that rope to something stationary, like the trunk of the same tree, at a convenient level maybe shoulder high or so.  Once it's tied off, I'd leave all the "excess rope" still connected, just coil it up and hang it there.  It will be needed one day when you want to lower the  pulley assembly.

Now you should have the "antenna hoist rope" up through the pulley with both ends on the ground.  Use one end to tie the dipole end insulator to, and pull the other end to hoist the wire up to pulley level.  Tie off the rope once it's up there.

Do the same thing at the other end of the dipole, with another tree!  Remember to connect your transmission line to the dipole before hoisting the whole thing up.

With practice (I've done this too many times to count!) you can get both ends up and have a working antenna in 15-20 minutes.

I like using pulleys at the ends, as it makes antenna upgrades or maintenance so much easier.

For very long wire antennas in trees that sway in the wind, instead of "tying off" both ends, it's useful to tie off only one end and tie a weight (maybe a 20 lb block) on to the other end a few feet above ground level, so the weight provides the tension on the wire antenna.  For longer, heavier antennas, it might take 30-40 lbs.  But the weight and pulley system will allow the antenna to "bob" up and down as the trees sway, relieving stress on the system that might otherwise break it.

WB2WIK/6
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K8AC
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Posts: 1477




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« Reply #2 on: June 21, 2009, 10:21:28 AM »

In recent years, a fellow ham in California developed a pneumatic antenna launcher (most of us refer to it as an "antenna cannon").  It can shoot a weighted tennis ball (4 oz.) over any tree that grows in this part of the world.  I use 20 lb. test fishing line to get the tennis ball over or through the tree, and then pull up a light braided nylon line with the fishing line.  That line is then used to pull up the rope that supports the antenna.  It's virtually impossible to get the tennis ball hung up in the tree, but pretty easy if you're shooting lead fishing weights.  With this device, you can shoot a tennis ball and line over a specific limb at heights of at least 100'.  Or, as we did recently, you can shoot a line over an entire stand of trees.  You set the air pressure in the tank for the distance you're going to shoot (comes with testing and practice).  A common bicycle pump is adequate to pressurize the tank.  Here's a link to the website with lots more info on the device: http://www.antennalaunchers.com/antlaunching.html

This would be a good project for a club or group of hams and would keep the cost down.  It's a very good idea, even when shooting tennis balls, for the crew to wear hard hats when standing "down range".
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KE4DRN
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Posts: 3734




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« Reply #3 on: June 21, 2009, 05:56:49 PM »

hi frank,

find a Wrist Rocket brand slingshot,
attach a small Zebco reel using cable ties.

you'll hit your mark in one or two shots.

similar to this expensive 'custom built' unit
http://www.ezhang.com/

you can make one for $20 USD.

73 james
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KF4HOQ
Member

Posts: 47




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« Reply #4 on: June 22, 2009, 08:43:53 AM »

One thing that I feel like needs to be added here:  check with your local law enforcement agency before using any slingshot or pneumatic launching device, as these items are sometimes regulated in some jurisdictions.  Usually in the U.S., these items are okay to use, but I can't swear about in the Netherlands.

Otherwise, have fun getting those antennas up!!

73!
Michael
KF4HOQ
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N3QE
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Posts: 2344




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« Reply #5 on: June 22, 2009, 12:56:39 PM »

Slingshot. Or tennis ball cannon. And a fishing reel. Followed by some twine. Then the actual support rope.

The trick is to not try to get it into the tree: just shoot over the tree.

With a tennis ball cannon it's really easy to not just clear the tree you want, but the ten trees behind it. The trick is to grab the fishing line just as it clears the first tree to stop motion, and let the weight fall down and through.
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NA0AA
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Posts: 1042




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« Reply #6 on: June 23, 2009, 10:31:30 PM »

Another ham reminded me of the "chuck-it" tennis ball thrower - it's a cheap plastic contraption - buy one of their heavy rubber balls and you can get a line a long way up with a very moderate throw - and it's not illegal or dangerous.

If it's for any length of time, how about hiring a tree climber - I think I paid about $200 to have a guy put two pullies in two trees about 4 years ago - well worth the cost.
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PA3GMP
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Posts: 75




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« Reply #7 on: June 24, 2009, 10:00:52 AM »

Thanks, everyone, for the helpful suggestions! I am definitely going to try out a few of them. With luck I'll be able to tell you all about it on HF!

73 Frank PA3GMP/ZS6TMV
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N4CDB
Member

Posts: 86




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« Reply #8 on: June 29, 2009, 11:55:25 AM »

KG6WOU wrote:
Another ham reminded me of the "chuck-it" tennis ball thrower - it's a cheap plastic contraption - buy one of their heavy rubber balls and you can get a line a long way up with a very moderate throw - and it's not illegal or dangerous.
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This is exactly what we used for Field Day. My friend modified one of the throwers for his dog's tennis balls and mounted a fishing reel to it. He weighted the ball with rocks and resealed it. I easily launched the line over a limb about 50-60' or so (maybe a little higher) on my 2nd or 3rd try. It worked very well.



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If it's for any length of time, how about hiring a tree climber - I think I paid about $200 to have a guy put two pullies in two trees about 4 years ago - well worth the cost.
********************************************************************************************************************

This is what I plan on doing at the house. I tried to get a tree service advertising on craigslist to do it but they never responded so I'm looking for someone else.
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W9FW
Member

Posts: 2




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« Reply #9 on: August 30, 2009, 04:45:56 AM »

If you\'re still looking for a way to put a wire antenna up in a tree try the EZ Hang sling shot.  I\'ve been using it for years without any problems and currently have a dipole up 80 feet between two trees.  Dennis, the owner, has come up with some new models and I can vouch for the quality of the tool and the top notch support he provides.  I gladly recommend and endorse the product.  It really works great and is easy to use.

73,
Jim - W9FW
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