Bigshot Slingshot to launch a line for an antenna
There are several tall trees at my NH QTH and I decided to put an antenna up as high as possible in one of them. I needed a way to accurately put a wire high up into the tree. I read about spud cannons used to launch a line up for an antenna and considered buying or borrowing one for the project. Around this time, I saw a device called a Bigshot Slingshot Throwline Launcher on a TV show about building treehouses and it intrigued me. It is heavy duty and can throw a 10 oz. or 12 oz. weight with a 3/8 inch line attached up 100 feet or more.
I found a deluxe kit on Amazon which contained the slingshot and trigger assembly along with spare elastic bands, throw weights, line, line bag, and carrying case. It is built robustly, to commercial standards and I was eager to try it out. I did a few dry runs and learned that it could easily launch the weight 75 feet up. For more height, set the trigger assembly lower on the pole to stretch the elastics more and launch even higher.
Caution!
An Important Word of Caution Here!! This device is powerful and can cause injury if not used carefully. Read all the instructions, wear eye protection, and like a gun, point it away from anything you do not want to break. I am 6’2” and 275 lbs. when cocking the elastics and straining against their pull this device lifted me from the ground and pulled me off balance with ease. I have a lot of respect for the power it has and you should too.
End Fed Half Wave Antenna at 50 Feet
I previously used this line launcher to install a MyAntennas.com 8010 EFHW antenna in my NH QTH backyard with the endpoint up in a tree 50 feet high. I was happy with the performance there for 6 months until I tried working in the CQ SSB DX WW contest. Before the contest, I logged QSOs on 20 and 40 meters all over the US, South America, Africa, and Europe, along with some 80 meter QSOs out to around 1500 miles. However, during the contest, I had difficulty breaking pileups, so I decided to try and raise the tree end of the antenna.
Preparing to launch the line
The line hanging from the tree is what held the antenna at 50 feet. I will tie the line to the throw line when I shoot it up to the higher branch.
I was trying for maximum height on this launch, so I moved the trigger assembly down on the shaft of the launcher a bit more than usual. It took serious effort to cock the launcher. Note, I am wearing eye protection and pointing the device away from my body.
Launching the line
First, you must untangle the throw line before launch. Carefully coil it into the throw bag so it will come out smoothly. The launch should be almost vertical to be able to get the maximum height out of it. Launching at 45 degrees or 60 degrees gets a long distance, but disappointing height. As a result, I think I was launching at 75 or 80 degrees here.
Success, the line is up around 70 feet in the tree
These two pictures fully show the tree to give some scale to how high the end of the antenna is.
This picture, looking South, shows the antenna feed point around 30 feet high at the house. There are three 10-foot chain link fence top rail sections attached to the corner of the house with a line holding the antenna. From there the ground slopes downhill around twenty feet. The end of the 135-foot wire antenna is hung at seventy feet in the tree. It is running North and South with a little bias to the West.
Did it work?
I was eager to find out if it was going to make a noticeable difference in the contest. It did! On the 20 and 40 meter bands I can get through pileups, often on the first or second try. My first QSO on 80 meters was to Ukraine, around 4500 miles away. In the beginning of May, during the NE QSO Party, for instance, I had replies to my CQ on 80 meters with only 100 watts from Italy and Uruguay. 80 meters was my most productive band in the contest.
Good for Christmas lights, too!
Here is a quick look at the throwline launcher in action. I am sending a line up in a tree to pull up some Christmas lights. Click on the picture to view the video. Each string of lights in the picture on the right represents the arc of the throw-weight and line. The max height in the tree is around 35 feet.
NARS Winter Field Day 2020
During setup for the Nashua Area Radio Society’s 2020 Winter Field Day the spud launcher, we were using broke after setting up a 40-meter delta loop antenna. We still had to set up the 160 Meter Transmit Antenna. It was a dipole, fed at around 50 feet with each end to be installed around 40 feet high. I made a quick trip home to fetch the throwline launcher. Upon my return it was easy to secure the ends of the dipole up in the trees.
Jon, AC1EV
