Category Archives: Safety

WT8WV “Colossus” Air Cannon Antenna Launcher

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These are the basic parts to make my “WT8WV Colossus” antenna launcher.

Folks, this has been a fun and hilarious winter project.  Yesterday, when I built this air cannon antenna launcher it was -4 degrees outside and this was a perfect evening project to put together.  For years, me and my two ham radio buddies (WR8S Bill Shultz and WV8TG Tom Graf), have enjoyed ARRL Field Day activities and usually used a slingshot and a 3/4 ounce fishing sinker weight and an old Zebco fishing reel (with 20 pound test line) to shoot and suspend our doublet dipole antennas high into the trees.  Certainly, the slingshot worked pretty much flawlessly… but… boys will be boys, and the idea of an air cannon / spud launcher / potato gun type system seemed to be a new desire.  (Most people, our wives included, wouldn’t trust our 3-man team with a slingshot, let alone a potato gun!  But I digress.)  Actually, our local ham radio club (Monongalia Wireless Association) had a version of a potato gun antenna launcher, so we decided we needed one of our own… and to make some design modifications in the interest of… “science”… plus our own sadistic pleasures.  (Make sure you read below WV8TG’s initial “pressure test” experience.)  The following pictures hopefully provide the basic concept and parts we used.  Tom and I split the cost of the parts needed to make launchers and each built our own version, but they both are the same basic design with only length dimensions of the air chamber and barrel being the difference.

All parts where sourced from our local Lowes store in their plumbing department, except the Schrader valve which can be purchased at an automotive store.  Total cost about $40 but you could make a couple of them as a joint project with a friend and reduce that cost per launcher a bit.  I got a small rubber gasket for the outside nipple of the Schrade valve to act as another seal on the exterior of the air chamber.  You will need to drill holes for Schrader valve, barrel slug stop and projectile slug caps to attach the screw eyes to attach the fishing line.  I used 3 inch PVC for air chamber, 1.25 inch PVC for the barrel and short sections to mate the air chamber, trigger valve and threaded barrel.  The projectile slugs were made from 3/4 inch PVC and caps and I filed off the nubs on the caps with a Dremel tool for a smooth fit into the barrel.  I used PVC Prep on each joint before applying the glue.  When gluing joints together, insert the sections together and twist a quarter turn for a solid adhesion.  Let all glue set up for 24 hours before testing air pressure chamber.  I will pressurize the chamber inside and let it sit overnight to see if it loses any pressure.  It’s too cold right now to take outside in -4 degree temperatures to test, but I will use a bicycle pump with a pressure reading valve, and start at 40 psi… then 50 psi… and then 60 psi for test shots to see how it functions and check for any air pressure leaks.  We use 60 psi for our club launcher.

WV8TG (Tom) charged his air chamber (barrel not attached) and let it set overnight to test for chamber air leakage.  When he opened the trigger value… there was NO leakage… but there was a sudden LOUD release of 60 psi air gush out of a 30 inch long, 3 inch wide fully charged air chamber.  He indicated the compressed air release was… impressive.  However, his wife was not impressed… nor was she aware of the scientific test that was taking place.  #surprise!  #WHOOOOOOOSH  #loudwifeexpressions  I have no reason to doubt Tom will find his projectile slugs in the next county using his design.  The club chamber was 12 inches long versus his 30 inch air chamber.  #overkill?  I designed my air chamber for 14 inches and will conduct all tests… outside.  #potentialmeanwife

 

 

 

 

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Intro to Kit Building for Radio Amateurs by K7QO (Chuck Adams)

Chuck Adams (K7QO) makes a club presentation on Kit Building basics.  He highlights what every ham radio operator needs on his workbench to build kits or make repairs.

K7QO Chuck Adams website

Amateur Radio Go-Box and Go-Bags Examples

Ham Radio Operators need to be ready to roll out to a crisis quickly if it requires communication support.  Are you ready to “grab and go”?  How quickly could you have a functional ham radio station on-the-air ready to support an emergency situation?  Could you support your local authorities efforts, and for how long?  Can you personally sustain yourself with food and water for 3 days of support, without being a burden on the emergency relief efforts?  Constructing your own version of a “Ham Radio Go-Box” and a “Go-Bag” might be a great addition to your preparedness efforts.  Below are some pictures of potential Go-Boxes to stir your imagination and creativity.  You might even have some of the items laying around that could be put into the effort to BE PREPARED.

GO-BOX IDEAS

GO-BAG IDEAS

See How a Schematic Diagram is ACTUALLY Visualized

“How to read an Electronic Schematic” by Paul Wesley Lewis

Wonderful example of how to visualize and equate the schematic diagram with the actual circuit build out.

How Do I Read a Schematic Diagram?

How to Read a Schematic by RimstarOrg 

If you are going to build a simple crystal radio, a QRP rig or even a 100 Watt HF transceiver, you are going to want to understand how an electronic schematic diagram is read.  It’s not that difficult.  RimstarOrg has a great video on understanding the basic concept of reading a schematic.

 

Multimeter Tutorial by AfroTechMods

THE BEST Multimeter Tutorial

The voltmeter… the Volt-Ohm Meter… the Multimeter… digital or analog… continuity… amperage, voltage and ohms… COME ON, MAN!  What is it and how hard is it to use in the every day life of a ham radio enthusiast or just someone working in their workshop?  Once again, Afrotechmods has an excellent tutorial on his YouTube channel for us to learn from!

 

 

Do Volts or Amps Kill You?

Does Volts or Amps Kill You? Voltage, Current and Resistance

This should be a good lesson for everyone, especially Hams that tinker and homebrew serious radio equipment.  You’d be surprised how much is too much!  Safety around radio equipment, coaxial cables, power chords, power lines, lightening storms, grounding straps and towers needs to be at the forefront of our mind.

Excellent YouTube video by RimstarOrg.

 

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playwithlifeorg

4 out of 5 dentists recommend this WordPress.com site

BG5TLA's Blog

Just another WordPress.com site

Tinkertoytech's Blog

Just another WordPress.com weblog

KC4LMD

Chronicling my pursuit of amateur radio’s "Worked All Neighbors" award

Casey's Place

"When we try to pick out anything by itself, we find it hitched to everything else in the universe." -- John Muir

Hackaday

Fresh hacks every day

VK4JAZ

Writings about Amateur Radio

Tactical HF

I love the smell of ozone in the morning...smells like...radio.

WB5RMG : RadioActive Blog

slightly sub-orbital testing facility

73, de N2HTT

A blog about ham radio, Linux and more...

Ham Radio Blog PD0AC

Thoughts of a Dutch radio amateur

Silver Bells Blog

Truth Appealing...

CQ de WT8WV... GraHAM's Dits & Dah's

My journey in amateur radio intrigues and hobby interests

K5UNX Ham Radio Blog

A blog dedicated to things Ham Radio related

Mountain Mists...

A pleasant journey into how I see things... big and small

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