We have covered Alan’s Biocca’s fantastic clearinghouse site antennalaunchers.com before, and Brookfield, CT, resident Andrew Stoev’s basic launcher design appears to be a slightly up-gunned version of Alan’s CSV19 pneumatic antenna launcher. Andrew describes his basic modifications of Alan’s design:

• Slightly larger compressed air tank – my launcher is using 10 inch length of the 4″ diameter pipe for the tank vs. Alan’s 8 inches. The reducing coupler I am using as part of the tank gives a little extra volume too.
• Longer barrel – 18.5 inches vs. Alan’s 16 inch barrel – I had lengthen the barrel a bit in order to account for the larger pressure vessel and have enough clearance for the Zip Reel.
• More reliable and safer pressure vessel – instead of drilling a hole for 1″ pipe and epoxy gluing the pipe for the high pressure outlet in a 4″ end cap, I am using a 4″ to 2″ reducing coupler and and 2″ to 1″ reducing bushing as part of my pressure vessel. Another advantage is that I don’t have to drill precision large diameter hole – unfortunately I don’t have a lathe.
• More reliable and safe coupling between the barrel and the high-pressure pipe – I am using 2.5″ to 2″ reducing coupler and 2″ to 1.25″ inch reducing bushing. It is much easier to assemble the launcher that way! Alan’s design yields for drilling a 2.5″ end cap and epoxying the 1.25″ inlet (actually, a 90 degree elbow) in the hole
• I made the spacer between the pressure tank and the barrel out of two pieces PVC, sliced from 4″ pipe scrap. I adjusted the curvature of each piece to follow the outside diameter of the corresponding pipe and glued the pieces back-to-back.

It’s a beautiful build, but my favorite feature is the quick-release mount he added for his Android device. Using a free app called GeoCam, his phone, when so mounted, becomes an augmented-reality aiming scope that provides GPS location, compass orientation, and (probably most usefully for this purpose) phone inclination data. [via Hack a Day]