Sigma BM-286A service manual Maintenance

5. MAINTENANCE page 34

5.2.1. Channel Boards, RCS-110:

Refer to "RCS-110 Schematic Diagram" Drawing 6 and "RCS-110 Component Designator" Drawing 7 (Appendix F.).

Oscilloscope set-up:

1 µsec HORIZONTAL\DIV

1 volt VERTICAL\DIV

This procedure must be performed for each detector channel in the system for a normal calibration.

NOTE:

The following adjustments are factory preset, and should not require further adjustment.

R15 should be turned maximum ccw to prevent inducing noise into the beta amplifier. R8 & R23 are amplifier offsets, and should not require further adjustment.

The factory settings are -0.005 volts at TP13 and TP1, respectively.

5.2.1.1. First Stage Pulse Amplitude:

The first stage pulse amplitude is set by adjusting the high voltage.

NOTE:

TP17 provides a divide by 100 test point for the high voltage. This test point should be monitored during calibration to verify that the high voltage does not exceed 1,400 volts, or 14 volts at this test point.

WARNING:

Exceeding 14 volts at TP17 could cause permanent damage to the photo-multiplier tube.

Model BM-286A