24 Nov
2007
24 Nov
'07
7:27 p.m.
From: cclist at sydex.com
On 24 Nov 2007 at 23:34, Tony Duell wrote:
Interesting--I've run into strobe discs for 45 rpm phono use that
claim that it's only possible to get a 50 Hz strobe lock at 45.1 RPM.
Let's see--45 rpm is 0.75 rev/second. 0.75 of 50 Hz is 37.5, but 75
at 100 Hz. So, a strobe disc with 75 divisions should appear to be
stable with a 100 Hz strobe light.
I wonder why the weasel words, then?
Hi
75 is a lot of bands. I'd think that it would need to be a larger
disk. Still 45 for a 60 Hz would be 90. Are you sure your not
thinking of 33 1/3. That is a lot tougher or 78.
Dwight
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Is it
possible to construct an accurate 50 Hz strobe disc for 360 RPM
drives?
Of course it is. I believe you can do it for any speed and light
frequency, sctually.