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Antenna Launcher

AI6US Antenna Launcher

A pneumatic line launcher built entirely from locally sourced PVC and irrigation
parts. Assembly takes a few hours; let the PVC joints cure for a full day before pressure testing.

Where to buy: Sierra Pipe, Home Depot and Ace Hardware each carried all the parts.
Start at Sierra Pipe.

Parts List

PVC Pipe

  • 16″ of Schedule 80 — 4″ pipe
  • 24″ of Schedule 40 — 2.5″ pipe
  • 24″ of Schedule 40 — 1″ pipe (ram rod)
  • 3″ of Schedule 40 — 1″ pipe

PVC Fittings

  • 1×4″ Sch. 40 cap
  • 1×4″ Sch. 40 slip to thread
  • 1×4″ male to 2″ female threaded reducer
  • 1×2″ male to 1″ female threaded reducer
  • 2×1″ to 1″ threaded coupler
  • 2×1″ slip to 1″ thread 90°
  • 1×1″ female to 1.5″ male threaded reducer
  • 1×1.5″ female thread to 2.5″ male slip
  • 2×2.5″ female slip coupler

Valve & Air System

  • 1×Rain Bird irrigation valve, 1″ female threaded in/out
  • 1×1/4″ NPT tank valve
  • 1×1/4″ NPT 100 lb air pressure gauge
  • 1×1/4″ NPT 90°
  • 2×1/4″ NPT to 1/4″ NPT
  • 1×1/4″ FNPT to 1/4″ FNPT shut-off valve
  • 1×1/4″ NPT to 1/4″ FNPT 90°
  • 1×1/4″ NPT air nozzle (removable tip)

Line & Projectile

  • 1×Open fishing reel
  • 1×350′ of 15–20 lb braided fishing line
  • 1×Tennis ball
  • 2×3″ hose clamps

Adhesives & Sealants

  • Teflon tape (or pipe dope)
  • PVC primer
  • PVC glue
  • Epoxy glue

Converting the Rain Bird Valve to a Manual Trigger

  1. Unscrew the Rain Bird solenoid.
  2. Remove the 6 screws securing the diaphragm top.
  3. Drill and tap the center of the diaphragm cover for the 1/4″ NPT air nozzle — this becomes the trigger release.
  4. Seal the solenoid air pass-through holes left behind with epoxy.
  5. Reassemble the diaphragm and secure it with the 6 screws.
  6. Use Teflon tape or pipe dope on all threads during final assembly.

Curing & Pressure Testing

Let all glued joints cure a full 24 hours before applying any pressure. Then step
the pressure up gradually, inspecting between tests.

Test Pressure Notes
1 20 lb Initial test after 24 hr cure
2 30 lb Check all joints and fittings
3 40 lb Check all joints and fittings
4 50 lb Tennis ball sailed away, never to be found. 🙂
Max 50–70 lb Do not exceed

Best regards!
Brian Gohl — AI6US