-----Original Message-----
From Tom Fine: "...Shai -- how about a stroboscope wheel in the tape
path?..."

I was told when I was working in motion picture post production that
unfortunately power line frequencies are not a reliable source of speed
calibration because they are adjusted to maintain the long term accuracy of
electric clocks.

A flutter tape is really the only solution.

Bob Olhsson Audio Mastery, Nashville TN
Mastering, Audio for Picture, Mix Evaluation and Quality Control
Over 40 years making people sound better than they ever imagined!
615.562.4346 http://www.bobolhsson.com http://audiomastery.com