RL02 Head install info

From: Paul Koning <pkoning_at_equallogic.com>
Date: Fri Feb 6 08:43:10 2004

>>>>> "Christian" == Christian Corti <Christian.Corti_at_studserv.uni-stuttgart.de> writes:

 Christian> On Thu, 5 Feb 2004, Tony Duell wrote:
>> bad head. I've never actually done an RL head replacement, but
>> I've done it for RK05s, and I remember just replacing a single
>> head if the other one was OK. The heads do not come as matched
>> pairs, any 'down' head will work with any 'up' head.

 Christian> There are definitely different kind of RK05 heads. We had
 Christian> to replace the heads from a RK05 drive for our LAB8/e just
 Christian> two or three weesk ago. Trying to align the heads with an
 Christian> alignment pack and executing the data reliability tests
 Christian> revealed that there are low amplitude heads and high
 Christian> amplitude heads as well as low amplitude disk packs and
 Christian> high amplitude ones. The failed head was a high amplitude
 Christian> one and we tried several low amplitude heads that wouldn't
 Christian> work together with the read/write amplifier card. At last
 Christian> we found a head pair with high output. Afterwards we
 Christian> found a small note in one ECO manual for the RK05 that
 Christian> mentioned high and low amplitude packs but not heads. Our
 Christian> scope (btw. a very good Tek 555!) proved that there are
 Christian> different heads, too.

That's puzzling.

On the other hand, I remember a difference between "up" and "down"
heads, which has to do with the way the heads "fly" above the disk
surface.

The heads need the right amount of pressure towards the disk surface
for the flying height to be correct. If it isn't, you'll get low
amplitude (flying too high) or possibly head crashes (flying too low).

For a head flying above the disk, gravity and the head mounting
springs are pushing in the same direction; for a head flying below the
disk, gravity is lifting the head away from the surface while the
mounting springs push it to the surface.

So I would expect a head meant to be above the disk to give low
amplitude if installed below the disk. In any case, this is one
explanation why it matters.

            paul
Received on Fri Feb 06 2004 - 08:43:10 GMT