RL02 drive measurements
I have version 3 of the RL02 controller, which looks as follows:
First test is the sector pulse timing check. For that the oscilloscope is on TP14. The signal looks as follows:
According to the docs this should be:
The downward voltage is about -0.7V which is within spec. The pulse width is 625uS which is ok (624uS is the medior).
Second is sector pulse width on TP11:
This should be 62.5uS; 62.8 seems close enough.
Positioner radial alignment:
We need to disable:
- SKTO (strap on tp23-tp24)
- Cover closed (strap 19-20)
- POS SIG (strap 25-26)
Place probe A on TP11 (sector pulse), place probe B on TP2 in the WRITE module.
The manual says this:
This manual image is confusing. It shows chA at 500mv/Div, and the pulse at 2divs = 1V. But we measured that pulse in the previous test and it is at 5V. I think the values have been swapped and channel A is on 2v/div and B is at 500mv. So the correct picture is this:
This looks OK; the servo burst arrives at 15.6 uS
Jitter fix
While doing the Head Alignment test I found that the signal had a very large amount of "jitter":
Doing the alignment reduced that to within spec (15 uS +/- 3 uS).