Re: Pneumatic antenna lanuchers

HF
 

I made and used one like Braden's for a while until I borrowed my friend's pneumatic launcher.  I'm too weak to shoot an antenna higher than 15 meters with my slingshot.  Building my pneumatic launcher required learning how to glue PVC pipe together which was much easier than I expected.  I used a $15 sprinkler valve meant for 24V operation (it works with much lower voltage than that). I put some nuts and bolts into an eye drops bottle and tied the fishing line to it as a weight.  It fits perfectly into the nominally 1-inch schedule 40 output pipe.  I used a $7 fishing reel with the 8-pound test line that came with it.  This launcher shoots higher than the very tall cedars and firs around here in northern Cascadia.  The 40-gram weight pulls the fishing line down over the branch, then I tie stronger line to it and pull it back.  Finally, I tie 1/8 inch polyester rope as a halyard to the stronger line and pull it through the third time.  I hope this summary helps the next person launch waves from the top of the canopy.  If anyone has ideas on how to make one of these launchers with total mass less than 500g, please chime in!  I want to build a version to take on backpacking trips with the QCX.
-Halden VE7UTS

Join QRPLabs@groups.io to automatically receive all group messages.