The service manual when downloaded and printed out was clear and easy to read. I would have liked to have been able to enlarge some details, but this was not possible as the file permissions did not allow this. The service was very good. The time taken from placing my order to downloading the document was only a few minutes.
Perfect source of information for replacing the HDD and performing general diagnostics.
Text excerpt from page 20 (click to view)
3-12.
Model 10811A/B Find the line on Table 3-1 corresponding to the oscillator's aging rate. Then find the maximum allowable error (accuracy) on the horizontal axis. Follow the maximum allowable error vertically until it crosses the oscillator's known aging rate. Move horizontally to the left and read the minimum calibration interval in days. maximum allowable error known aging rate (per day) = calibration interval in days
Example: 5 x 10-9 (maximum allowable error) 3 x 10-10/day (known aging rate) 3-13. 3-14. = 16.67 days (~17 days) 3 X 10-10/day (known aging rate)
From Table 3-1, the oscillator should be adjusted approximately every 17 days. The minimum calibration interval may also be determined from the following formula: