[TowerTalk] Tennis ball launcher

[W7ZZ]

I use an antenna shooter based on an article that appeared in QST about 18 months ago,a design later modified by a member of the Radio Club of Tacoma.  It shoots a PVC projectile easily 150' in the air and yet the projectile is heavy enough to pull the fishing line down on the other side.  I use a yellow 60 pound test dacron line -- easy to see in the tree and wears like iron.  It is very easy to aim, unless it is windy.  If you want to shoot something lower than the maximum height, you just fill the air tank with less pressure.  I use a bicycle pump that has an accurate pressure meter on it but my shooter also has a pressure guage.  If the two differ, I use the average of the two.  You shoot the projectile over the tree (or limb of your choosing -- it's pretty easy to aim) and then cut off the projectile, replacing it with light line (I use 550 parachute cord).  You then reel the parachute cord back over the tree.  If need be, you can then pull a heavy line back using the parachute cord to pull it with.  The parachute cord is incredibly strong, wears like iron and has stretch built in, which adds some shock absorption to the system.  

The North Kitsap Amateur Radio Club sells a tennis ball launcher that shoots weighted tennis balls.  It's much smaller than my launcher and works even better.  When mine eventually breaks, which it will as the components are all ABS or PVC, I'll buy one, they're so good.  Again, using colored balls and line, it's very easy to work with even in dense foliage/trees.  They use a 12 volt air compressor to fill the shooter, but a bike pump would work just fine.  The NKARC shooter has a pressure guage and uses a trigger release valve system (mine uses a PVC shutoff valve -- more crude, but works just fine).  I suggest you contact W7PV, Paul Voorhees, and see if there are any "in stock" at the moment.  I think they go for $150 and worth every penny.  Here's Paul's email:  ropavo at gmail.com  I will copy him on this message so that he knows this is being blasted out to the TowerTalk reflector.

By the way, for years I used the slingshot/closed face spinning reel method.  In my opinion, it's dangerous and I had many fishing sinkers swaying in tree branches way up in the air when the sinker spun around a branch rather than passing through it like a tennis ball or my PVC projectile would do. Sooner or later, those are going to fall and hopefully there won't be anyone underneath at that moment.  Also, on occasion, the sinker will hit the tree trunk or a branch at high velocity and then it can bounce straight back at the shooter --- very dangerous, it happens so fast you can't even get out of the way.  Having said that, I confess that I still use this method if I don't want to shoot very high. The antenna shooters described above don't work very well at lower heights.

73, Doug W7ZZ