RL02 Head install info

Christian> On Thu, 5 Feb 2004, Tony Duell wrote: 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