26 Jan
2014
26 Jan
'14
6:12 p.m.
Isn't the alignment disc essentially a series of
concentric analog
sine-wave audio tracks, with each audio track recorded on the centerline of
a disc data track?
Actually, they are deliberately recorded eccentrically, so that as the
disk spins the ampllitude of the signal seen by the head changes. That's
what gives the catesye apttern.
It would seem that so long as the drive uses the same track spacing, one
disc could serve many mechanisms. Please correct me on that, if needed.
I beelive there are versiosn for drives with diffenent head azimuth
angles (the angle ebtwene the head gap and a radius of the disk). In my
experience this doesn;'t seem to matter to much. Yes, there is a head
azimuth test, but azimuth is rarely field-adjustable anyway and I've
never needed to check it. Radial alignment is the important one.
-tony