Safely Getting a Cord Over a Branch
Safely Getting a Cord Over a Branch
Or how to avoid shooting arrows and other dangerous projectiles in a public park!
I was going to buy or build a pneumatic launcher to get a projectile and messenger line over a tree branch. You know how that works: attach a stronger cord to the messenger line and pull that up, then pull up your antenna…or if the messenger is strong enough, just attach the antenna and pull it up. Some people use slingshots. Some people use a bow and arrow system.
I had second thoughts about the safety of any approach that launches something hard or pointy up, up, and away in a public park setting. This comes after observing people literally walking right into my MFJ tripod holding the MFJ-2286 Big Stick antenna. Even though I had placed it away from people and away from obvious paths and trails, people still managed to walk exactly through that point, heads down and mighty surprised to find an antenna toppling over in front of them.
This is when I realized that sending projectiles over branches would never be safe with people around. And so I scratched my head and thought about this while I went about other things in my life.
Eventually, I remembered one of my favorite toys when we had dogs: a Chuckit!® ball thrower. If you’ve played with one of these, or seen someone doing so, you know the ball can be thrown a long distance.
My favorite antenna is the Chameleon Lightweight End Fed Sloper. That antenna wants to be at least 25-feet in the air at the feed point. Says Chameleon:
When installed at around 25 feet, this antenna will provide good general-purpose communication…The main advantage of the Sloper for portable operation is that it requires only one end support and is fast and easy to setup.
Surely, I thought, I can chuck a ball 25-feet into the air with a light line attached.
And so I bought a Chuckit! and some of their Ultra balls. These balls are made of a tough rubbery plasticky substance rather than being the fuzzy tennis-ball-like balls you might first think of. I screwed a small screw into the ball and liberally applied a cyanoacrylate glue to the screw. While it was still tacky, I tied on a 100-foot length of Spectra cord and then added more glue to the knot. After letting it dry, it was time for a test.
Boom. The first strong huck with the Chuckit! took my line over a branch more than 20-feet in the air. Winner.
I tossed it into a few different trees and hauled it back through the branches to see if the screw would pop out, but it held up. I think this will be my Parks On The Air (POTA) launcher for my wire antenna.
The whole thing is compact and quick to deploy. The biggest problem so far is keeping the line from tangling. It’s not as slippery as fishing line, but it’s so strong that I can attach the antenna to the line and pull it back up in the tree.
This won’t change the world, but it will surely help me feel more comfortable about trying to safely get a line over a branch in a public place. I don’t know how durable this will be but testing that will likely be fun!