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Pneumatic antenna lanuchers

Brad Thompson
 

Hello--

Through the magical properties of plastic plumbing parts and compressed air, you
can deploy skywires to amazing heights...

http://www.antennalaunchers.com/antlaunching.html

Be aware that hypervigilant neighbors may get nervous when you brandish
something that looks like a shoulder-fired missile launcher<g>.
73--

Brad  AA1IP

--
Sent from Postbox

Braden Glett
 

Here is my trusty antenna launcher that has served me long and well. Lightweight, cheap (all parts available at the sporting section of Walmart), and accurate. Also easy to prevent overshooting.

jjpurdum
 

I used one of these a long time ago and I'm pretty sure the lead weight is in near-Earth orbit as we speak...

Jack, W8TEE

On Friday, June 21, 2019, 9:18:08 AM EDT, Braden Glett <bradenglett@...> wrote:


Here is my trusty antenna launcher that has served me long and well. Lightweight, cheap (all parts available at the sporting section of Walmart), and accurate. Also easy to prevent overshooting.

DK
 

I had a student once ask me if he could bring his Linear Vegetable Accelerator (LVA) to my college chemistry lab. 

We turned his LVA into a lab experiment ( more of a physics experiment, but what the heck) by estimating the flight path of a potato as a function of air pressure used in the LVA.

We abruptly stopped the experiment when the potatoes flew over the distant trees and into moving traffic.

Science is fun!!!

DK. KD6TK 

On Jun 21, 2019, at 6:44 AM, jjpurdum via Groups.Io <jjpurdum@...> wrote:

I used one of these a long time ago and I'm pretty sure the lead weight is in near-Earth orbit as we speak...

Jack, W8TEE

On Friday, June 21, 2019, 9:18:08 AM EDT, Braden Glett <bradenglett@...> wrote:


Here is my trusty antenna launcher that has served me long and well. Lightweight, cheap (all parts available at the sporting section of Walmart), and accurate. Also easy to prevent overshooting.

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