Got the Slingshot Strap

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Originally Posted by WN9HJW

I never had much luck with a slingshot (I have an EZHang).

A couple weeks ago I had a tree service here doing some work. I watched one of the guys use a weight and rope to get a line up into the trees then pull up climbing ropes. He was getting lines up 60+ feet with little effort. Had a brief chat with him about what he was using, then ordered an Arborist Throw line Kit. Used it today to string a 20 meter dipole. Works great with a little practice.

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I took a look at the site you linked, and couldn't believe the number of different kits available. I'd go nuts trying to decide which one to get. Their marketing department has certainly done it's job. It's the old "for just a few bucks more, you can move up to a little better unit". This is where I start out looking at a $40 unit, and end up with the $2000 upgraded deluxe unit. And it happens by going up $5 at a time. Of course, since my Palo Verde trees are only 20 feet max, a rock and some rope would do nicely, but at that height, the antenna would be useless.

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Originally Posted by K7SGJ

Of course, since my Palo Verde trees are only 20 feet max, a rock and some rope would do nicely, but at that height, the antenna would be useless.

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Wouldn't be that bad for any dipole made for 17m and up. For 20m and lower, yeah, not so good.

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Several years ago, I built a "air cannon", like a "potato gun" only work's on compressed air.
I sized the barrel at 1 1/2 " and used PVC (sked 80) for everything.
The barrel will accept a "GOLF BALL" with a little wadding quite nicely, with 80 pounds of air it will send a golf ball out of site.
Drilled several golf balls (a few "squirted"), attached braided line and can now hang a line in ANY tree.
Out here in the "sticks" none of the neighbors get at all excited about much of anything and since the cannon makes very little noise even the xyl doesn't know when I hang a wire,,,, guess there are some advantages to living in the country.

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Originally Posted by W9WLS

Several years ago, I built a "air cannon", like a "potato gun" only work's on compressed air.
I sized the barrel at 1 1/2 " and used PVC (sked 80) for everything.
The barrel will accept a "GOLF BALL" with a little wadding quite nicely, with 80 pounds of air it will send a golf ball out of site.
Drilled several golf balls (a few "squirted"), attached braided line and can now hang a line in ANY tree.
Out here in the "sticks" none of the neighbors get at all excited about much of anything and since the cannon makes very little noise even the xyl doesn't know when I hang a wire,,,, guess there are some advantages to living in the country.

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Trouble with an urban area is that all the neighbors want to know "what is he doing".

First there was the slingshot. It was put together with about $25 worth of stuff from Walmart:

http://ae1pt.com/photos/imh/shot_parts.png

While this worked pretty well for 4 years and three slingshot bands--the best I could really do with it was about 50'. On a good day with no wind... :yuck:

This year I HAVE THE SOLUTION:

http://ae1pt.com/photos/imh/launcher.png

Now this is the real deal. 90' in the air? No problem.

Kits are available, and parts can be had for ~$100. It gets cheaper if several hams go in together and get enough stuff to make a half dozen or so.

Yessir, I built myself one of those. Mine is better looking... its blue. :lol:

I also use a spearfishing reel instead. POP! Over 120' with 40 PSI. :yes:

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Originally Posted by AE1PT

First there was the slingshot. It was put together with about $25 worth of stuff from Walmart:

http://ae1pt.com/photos/imh/shot_parts.png

While this worked pretty well for 4 years and three slingshot bands--the best I could really do with it was about 50'. On a good day with no wind... :yuck:

This year I HAVE THE SOLUTION:

http://ae1pt.com/photos/imh/launcher.png

Now this is the real deal. 90' in the air? No problem.

Kits are available, and parts can be had for ~$100. It gets cheaper if several hams go in together and get enough stuff to make a half dozen or so.

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Pat, what size PVC is the barrel? And do you have any information on the valve?

Thanks!

It's 2.5" schedule 40. Here are the instructions on how to modify the sprinkler valve:

http://specialized-weapons.wonderhow...cannon-210134/

One thing--don't use epoxy putty like this guy says. It will leak air slowly around the threads. Put a piece of tape on the underside of the hole, and fill the thing from the top with JB Weld epoxy.

If you want to string 3 9V batteries together, one can keep the solenoid and fire it electrically.

Thanks Patrick! Just what I was looking for! People are selling these things for big bucks. I just want one I can use.

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Originally Posted by WØTKX

Yessir, I built myself one of those. Mine is better looking... its blue. :lol:

I also use a spearfishing reel instead. POP! Over 120' with 40 PSI. :yes:

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Does it require blue balls?

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Originally Posted by n2ize

Trouble with an urban area is that all the neighbors want to know "what is he doing".

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No John, not a problem with that here.
If anything, when doing an antenna project (or anything else out side for that mater) IF one of the neighbor's notices they are more likely to stop and ask if they can help.
We are more "RURAL" than urban here, nearest neighbor is about 75 yards away, and then the next closest is about 1/4 mile , out here we watch out for each other but don't get involved unless help is needed or asked for.
Even the mail carrier has stopped to help me haul a line up a tree a couple of times.
That's life on the country !

A bit of update information! In looking for existing designs using the Saunders Zip reel (an archery spool), I ran across this article. It goes into great detail, and takes the reader to other primary sources of build info:

http://blog.kotarak.net/2011/04/say-...le-friend.html

http://www.akbeng.com/

http://www.antennalaunchers.com/antlaunching.html

These links are related. Lots of information. It's where I bought my kit. IIRC Saunders is the source of the reel I have on mine, through these folks linked above. Used their recommended higher pressure PVC cement, which is a two part process. The stuff cures to a light purple. While a little spendy, the kit was great. Included all the parts, and all the PVC was pre-cut.

Recommended. I hope to use mine today to get a 140' doublet up, after other chores. Here's a piccie...

https://lkoh9g.blu.livefilestore.com...her.jpg?psid=1