24 Nov
2007
24 Nov
'07
11:58 p.m.
On Sat, 2007-11-24 at 00:02 +0000, Tony Duell wrote:
My frequency counter, an old HP, has a test mode that does exactly that.
While it's obviously no use for checking the frequency of the mast clock,
it is useful for verifying that the clock divider chain and gate control
logic are working correctly.
-tony
That said, the only drives I have which are
360rpm are 8" ones iwth
mains-powered motors. Since the spindle speed is determined by the mains
frequency (unless the belt is slipping or something), there's little
point in having a stroboscpe disk o nthe spidnle, to check the speed
against that same mains freqeuncy. So I've never seen a strobe sdisk on
such a drive.
I'm vaguely reminded of my late father absent-mindedly fiddling with the
frequency counter he built, and (momentarily) being terribly impressed
that its 1MHz clock was running at dead-on 1000000Hz...