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From: jones@fortune.UUCP
Newsgroups: net.micro.pc
Subject: Re: Tandon Disk Drive Problems - (nf)
Message-ID: <2235@fortune.UUCP>
Date: Mon, 9-Jan-84 23:03:43 EST
Article-I.D.: fortune.2235
Posted: Mon Jan  9 23:03:43 1984
Date-Received: Wed, 11-Jan-84 03:10:28 EST
Sender: notes@fortune.UUCP
Organization: Fortune Systems, Redwood City, CA
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#R:inuxc:-88900:fortune:14700002:000:1952
fortune!jones    Jan  9 19:22:00 1984

I agree with Phil, but there is no particular reason why a diskette
with extra clamping pressure would make unusual noises.  The 
important thing to remember in the floppy world is that *nobody*
is perfect.  The best you can do is go with the vendors which
have the highest average quality or take it upon yourself to 
check to actual performance.  Bye the way, the diskette 
clamping pressure is set by the door adjustment.  The door
hinge is attached to the spindle lever arm through two screw
slots.  When the door is closed, the position of the lever
arm with respect to the door guides is set by those screws.
You could probably get it right if you are careful and willing
to do over and over.  I wouldn't recommend it to most people.
When correctly adjusted, and I quote, you must "ensure there 
is a 0.010" +/- 0.001" clearance between the E-ring (aside -
E-ring is what holds the cone/spindle) and the washer when
the cone is clamped - the result of the front door being
closed".

Diskette envelopes not seating correctly are a possible noise
generator.  Out of tolerance envelopes can also cause data 
errors since they affect the head to media interface.

On second thought, I guess you could generate noise with
improper clamping, but that would take some heavy duty clamping.
Are the hub re-enforcing rings on both sides of the diskette?

Just to muddy the water a little more, some vendors (like Shugart)
are real particular about which side of the diskette the hub
ring is placed since they believe it affects the critical head
penetration of head 1.  A while back Verbatim was evaluating a
thin built up polymer hub ring....that looked good.  Gosh, how
it all comes back as I think about it, another consideration is
that the hub ring can act as an insulator which may allow static
charge to build up on the diskette as it brushes by the liner, to
be discharged by the head.

I hate floppies, I really do.

Dan Jones
Fortune Systems Corp