Zenith Z-100 Series, Technical Manual

Page: 377 / 493

Page 6.37
CALIBRATION
Data Separator Calibration
Perform the calibration as follows:
1. Tu r n t he Computer on. Allow at least five minutes for
the Disk Controller Card to r e ach o p erating tempera-
ture.
2. Ma k e sure the disk drives are not selected.
3. Se t t he DVM's voltage range to 2 V. Attach the common
lead to GND and the positive lead to CP2.
4. Adj u s t R2 (shown in Pictorial 6-5) for a reading of 1.400
V.
5. Rem o ve the voltmeter test leads.
6. Set t h e six-digit frequency counter to count 4 MHz.
7. A tta c h t h e s h i eld lead to GN D a n d th e s ignal lead to
CP1.
8. Adj u s t R1 (shown in Pictorial 6-5) for a reading of 4.000
MHz.
9. Rep e a t Steps 2 through 8 until there is no further im-
provement and the 1.4 V and 4 MHz readings occur
simultaneously. There will be some (but not much) inter-
action between these adjustments.
10. R e m ove the test leads and turn the Computer off.
This completes the calibration procedure.
NOTE: Format the blank diskettes used in this procedure
again before you use them for recording files.