A DIY Antenna Launcher – for pennies

There are countless methods of launching a wire antenna into a tree that have been written about online. For example a PVC pipe air pressure machine. Sounds downright dangerous to me. Maybe they work just fine, but what if one of the joints isn’t glued properly and the darned thing explodes in your face? Besides, its a rather large piece of kit to haul up a mountain or out into the bush.

An old faithful is the slingshot used to fire a fishing weight on the end of a long length of nylon line. There are several drawbacks to this method, not the least of which is the use of slingshots being illegal in some jurisdictions. A slingshot can get a line very high into a tree, but just how high do you really need to go? For field expedient, temporary antennas, around 30 feet works well in many circumstances.

A simpler method involves throwing a weight attached to a line up over a branch. Some have suggested using a water bottle as the weight. Others prefer to invest in an arborist throw line with a leather pouch filled with half a pound or more of steel pellets acting as the weight. If it works for the professionals it’s gotta be good right?

My own method is constrained by my unique inability to throw anything in a straight line. I have written before about my baseball pitching skill of picking off runners on first base – while aiming for the plate! So I devised my own highly efficient method of launching antennas into trees that works and it’s cheap, really cheap.

The arborist method is great if you have a good arm and fine hand/eye coordination. If you don’t mind investing in professional tools only to see your investment irretrievably stuck in the brush at the top of a tree then go for it. An alternative is to make an antenna launching kit yourself with materials you probably already have, or can get for free, or in a pinch, can buy at a dollar store.

Here is what you will need:

• Latex party balloons (dollar store). Brightly colored balloons are easier to spot when your line gets stuck in a tree, or falls into long grass
• A small quantity of dry, fine sand
• Some small steel key rings
• About 100 feet of mason’s twine (dollar/hardware store). It is strong, yet very lightweight and slides through a tree quite well. I prefer a “woody” color like green because I use it to haul up my temporary field antennas. Woody colors keep the installation stealthy
• A couple of short lengths (about 12-18 inches) of paracord
• A small piece of rugged cloth, e.g. canvas or leather, about 9 inches long and 6 inches wide
• A trekking pole from which the tip has been removed leaving a smooth, tapered surface

Making “Sand Grenades”

“Sand grenades” as I call them, form the weights needed for the DIY arborist throw line. To build each one of these you will need 2 balloons, 4 ounces of sand and 1 key ring. I suggest making several sand grenades because Murphy says you will lose them. I have lost several by getting them stuck in a tree or overthrowing them into a swamp.

• Step One: stretch the balloons, then roll one of them along its length and, with a bit of jiggery-pokery, insert it inside the other balloon
• Step Two: Insert the tip of the funnel into the balloons and fill with sand. A kitchen scale is useful to measure the weight required
• Step Three: Tie the neck of the balloons around the keyring

Making a “David and Goliath” Sling

This style of sling comprises a canvas/leather/cloth pouch that is pinched together at the ends with a short length of paracord tied to each end. The size of the pouch should be sufficient to allow a sand grenade to nestle inside without falling out.

How to Use the DIY Antenna Launcher

Tie one of the pouch’s paracords to the end of a trekking pole, about 4 inches from the tip, using a robust knot such as a constrictor knot. You do not want this end to leave the trekking pole or else your sling will follow the rest of your kit up into the tree!

Tie the paracord at the other end of the sling’s pouch using a slip knot. This end should lightly grip the pole near its tip. It will fly off and release the sand grenade as the launch is executed.

Why use a pole? In the bible story David did not use a pole to operate the sling with which he killed Goliath. But there was an ancient weapon used by the Romans and others (a “pole sling”) in which a sling was attached to the end of a long pole. The pole provides mechanical advantage to increase the range and velocity of the projectile.

Now attach one end of the mason’s twine by tying a bowline knot with the loop about 4 inches long, then pass the loop through the keyring and back over the balloon. Secure the far end of the twine (e.g. with a tent stake) and place the sand grenade in the sling pouch.

Place the trekking pole over your right shoulder with the payload behind you, then flip the pole sharply upwards into a vertical position. The sling will release the sand grenade which will travel 30 or 40 feet (hey, maybe more – how’s your arm?) up into the tree.

An Even Simpler Alternative

A simpler alternative to using a pole sling is a dog ball launcher. Simply substitute the dog ball with a sand grenade and fire away. I have used this method too but since I often carry trekking poles on my back country field operations anyway, I prefer the pole sling method.

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