Crash Cart A number of years ago at an ACM SIGCSE Technical Symposium, there was a presentation from a school that created a data communications cart on wheels. This cart, amongst other things, contained a large spool of twisted pair wire, an oscilloscope, and a signal generator. The instructors would use the signal generator to insert a square wave (digital signal) into one end of the spool, and then connect the oscilloscope to the other end of the spool of wire. By observing the received signal on the oscilloscope they would see what happened to the signal as it propagated through the coil of twisted pair wire. Interesting questions to address:

• What happens when we increase the length of wire? Shorten the length of wire?
• What happens if we pass a magnet near or through the spool of wire?
• What happens if we increase the data rate of the signal injected into the spool of wire?
• What are some other things we can do to alter the signal passing through the wire?