John Woodgate wrote:

I read in sci.electronics.design that Terry Pinnell
wrote (in
) about 'PC CPU fan', on
Mon, 3 Oct 2005:

Thanks Glenn. All 3 of my HDs are Maxtors (2 x 60GB, and this latest
200GB), and all are 7200 rpm. Are you speculating that one might be
spinning at 432.000 kHz, and the other at 432.001 kHz?!

I think you multiplied by 60. 7200 RPM is 120 Hz.

Oops! That makes a lot more sense, thanks g.

So is it plausible that a HD1 could be spinning at 120 Hz and HD2 at
121 Hz (7260 rpm) to cause such a 'beat'?

--
Terry Pinnell
Hobbyist, West Sussex, UK