[pianotech] Tuning fork puzzle

[Ron Nossaman]

This happens twice
> with each full excursion of the tines, so the contact pulse at the 
> handle bottom is twice the frequency of the fundamental.
> Ron N

Incidentally, you can see this in the FFT display in Tunelab. 
The fork in air registers the fundamental. With the handle 
pressed on the table top, you get both the fundamental, and an 
octave peak.
Ron N