Standing Wave (Rubens' Tube Experiments)

For signal processing , a laptop computer with an open source audio synthesis program named Audacity ' It generated the frequencies for the experiment . I ran wire to the speaker from the computers headphone jack . This custom adapted cord was brilliantly engineered by the author of this . I used a cord that had a headphone plug on one end (this fit into my computer 's headphone jack ) and the other end was two male RCA style plugs which I cut off and made the appropriate connections to the positive ) and negative (- ) terminals of the

speaker

IMPORTANT ! It is important that the tube is mounted securely to a solid structure and kept away from flammable materials ! I used some brackets made to mount piping to walls and ceilings and secured the flame tube to an old office desk . The apparatus generates a lot of heat and bursts of flames occasionally . Safety goggles are a great idea as is a welding apron if you possibly can . use common sense and stay healthy !Assembly

It is ideal if the tube can be mounted in the area where both the construction and the experiment will be conducted . In any event , fasten the tube and draw a line down the length of the pipe . Along this line mark every 15mm 1 /2 inch ) from one end to the other . This is where the holes will be drilled

Location of drill-holes2 . Drill out all the marks you just made with the 1 /4 inch drill bit

3 . On one of the end caps , drill a hole large enough for the brass welding hose adapter (3 /8 inch

The image on the left shows three different sizes of adapter . I drilled a hole that is smaller than the threaded end so it would be snug in the hole...