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Re: [Phys-l] [tap-l] speakers


On 2011, Apr 26, , at 12:53, John Denker wrote:


Electrical reflections in this situation? I very much
doubt it.

Do the math: The signal propagates down the wire at the
speed of light, within a factor of 2. The length of the
wire is usually not more than 25 feet, i.e. 50 feet round
trip. Therefore the timescale for reflections is on the
order of 100 nanoseconds, corresponding to 10 MHz.


Yes that's why one must have a fast o'scope or many yards of cable.


bc used a corner reflector, o'scope, and a fast LED and detector to define the meter.