Pneumatic Antenna Launcher User Manual
Introduction
This document covers use of the CSV19 and CSV17 (or PADS) Pneumatic Launchers for launching lines. These lines are typically used for hoisting antennas for Emergency Services and Ham Radio use. These systems have been designed to increase the safety of this activity compared to the common techniques of slingshots and metal weights or bow and arrow launching.
These launchers use air pressure to launch tennis balls towing light fishing line over trees. The tennis balls are launched at velocities lower than a Tennis Serve. The balls are slightly weighted to reduce the velocity needed to carry the line. They are soft and highly visible to increase safety.
For more information see the web at http://www.AntennaLaunchers.com∞.
This document is available online at http://www.akbeng.com/w/LauncherUserManual∞
This document is available online at http://www.akbeng.com/w/LauncherUserManual∞
Building a Launcher
If you are building a launcher from a kit, or from scratch, see the CsvKitInstructions.
If you are preparing Tennis Balls for Launching Service, see LaunchBallPrep.
If you are preparing Tennis Balls for Launching Service, see LaunchBallPrep.
Unpacking and Reassembling
Launchers are occasionally shipped with the main valve disassembled to reduce chance of shipping damage to the trigger subsystem. See CsvReasm for instructions on reassembling the Launcher.
Launcher Safety
The Tennis Ball is propelled from the Launcher at (up to) velocities similar to a hard serve in Tennis. This is enough velocity to cause severe eye injury at close range. Always keep the launcher pointed in a safe direction, and do not pressurize the launcher until ready to launch. Eye protection such as goggles is recommended for those in proximity to the pressurized launcher.
Power Lines
Do NOT launcher near or over high voltage power lines!!! Launch lines may be sufficiently conductive to cause potentially fatal shock or arc flash explosions.
Operational Temperatures
PVC loses strength at both low and high temperatures. Do not use a PVC launcher that is outside the range of about 10 to 40 degrees C (50 to 100 degrees F). Do not leave launchers in direct Sunlight for extended periods of time.
Pressure Safety Relief Valve
If the pressure rating of the materials is exceeded the pressure chamber or valve may burst, potentially creating high velocity plastic fragments. Avoid exceeding the safe pressure ratings of the materials at all times. A Pressure Safety Relief Valve is recommended to prevent overpressure. Overpressure is especially possible with high pressure systems or small unregulated electric pumps that can reach high pressures.
Periodic Maintenance
Inspect the launcher thoroughly each time it is prepared for use. Insure there are no cracks or other damage. Damaged launchers should be repaired, disabled or destroyed. Removing the main valve top is a good way to insure that the launcher is not pressurized. See CSValveRemoval.
Pressure Testing
Annual pressure testing is advised. See LauncherTesting.
Hazards and Personal Protective Equipment
The hazards in Antenna Launching include:
- High velocity Tennis Ball
- High velocity Fishing line
- Falling debris from Trees
- Plastic Fragments from a broken launcher
- Other hazards from the application environment
The recommended Personal Protective Equipment includes:
- Safety Glasses
- Hard Hat
- Leather Gloves
- Closed toe Shoes
Launching Lines for Antennas
Planning the Launch
Select the supporting trees for the Antenna. Considerations include:
- Tree Height
- Suitability to support the Antenna Weight
- Spacing between the Trees
- Clearance Behind and Between the trees to get the Antenna up
- Proximity of Power Lines
- Proximity of vehicles, tents, buildings, and other items that might interfere with the installation or be damaged by errant balls
Tip: Launching over the top of the tree generally results in fewer problems than attempting to thread through the branches.
Selecting Launch Direction
The Launch Line is used to pull up a light support line, so launches generally are from the Antenna side launching out away from the Antenna. For a heavy antenna (such as a triband beam), the light line is used to pull a heavier line, so the launch is from the outside toward the antenna.
Selecting Trajectory
The height and distance of the launch trajectory can be selected to produce the most effective result. Launching too far can cause the line to get involved with trees behind the target. Launching too high allows the breeze to move the line away from the desired location.
Standing closer to the target tree reduces the distance the launch will go. Start about 20 feet from the tree (7 meters) and adjust as needed. To launch over a few trees at once start about the tree height away from it. Adjust as needed.
Selecting Launch Pressure
High launch pressure increases the velocity, height and distance covered by the ball. Launching too or too short can cause tangles. Optimal launches go as high and far as needed but no more. If you need a high performance launch (150-200 feet high) use full pressure (90 psi). Otherwise reduce it as needed. Typically 40-60 psi is adequate.
Preparing for Launch
Attach the line to the ball. Two techniques for doing this: Tie the line to the loop, and cut it, or tie a loop in the line larger than the ball and thread this loop through the loop and around the ball. In the loop case the ball can be detached without cutting the line.
Push the ball down the barrel all the way. Situate the line as needed from the reel going into the barrel.
Move to the launch position. Insure personnel in the area are aware of the imminent launch and have appropriate safety gear. Insure the landing area is clear. Pressurize the launcher.
Safety Tips: Avoid carrying a charged launcher around. Pressurize at or near the point of launch. Point the launcher in a safe direction, even when it is not charged.
Launching
Hold the launcher at arms length. Put the right hand on the trigger, and use the left hand to support the pressure chamber. Point the launcher slightly above the tree. Operate the launcher by pulling the trigger quickly without moving the launcher and spoiling the aim.
After the Launch
Untie the ball from the line and tie on the mason twine. Wind the launch line back on the reel, towing the mason twine over the tree. Untie the lines and attach the mason twine to the antenna, or to the heavier line and pull it up...
Troubleshooting
If you have problems with your launcher, see CsvTrouble.
AlanB (send comments on this document to the author at left)