TM 9-4935-481-14-1
C2
EQUIPMENT NOTES
EQUIPMENT NOTES
1. The Maintenance Calibration Procedure is performed to calibrate the overall DMS-D, stimuli and monitor, as a system. 8. When performing the phase adjustment at step 256, it is necessary to verify that the scope A & B sweeps are vertically
centered at zero (with no signal applied). Repeated checks & adjustments may be required until the scope has
When a circuit card or power supply is replaced, only the circuitry which is affected by its replacement will require
completely stabilized.
calibration. The procedure is arranged in sections, Power Supply, Master Clock and Voltage References, Horizontal
Wire Simulator, and Trainer Performance, etc., for the ease of calibrating when repair of a unit has been made.
9. When unable to adjust the ALIGN 1 control to a zero reading on the DMM, check the DMM offset.
2. When equipment failure indications occur, re-run the procedure to check for operator type errors.
10. When observing AC readings, allow the DMM to completely stabilize.
3. When monitoring with DMM probes at TB1 and TB2 on the DMS-D main power supply, insert the probe through the holes
11. In the LO FREQ Oscillator Calibration, steps 421 & 422, the oscillation is considered stopped when the output voltage <
in terminal board cover.
20MV PP. When stimulating the circuit into oscillation, potentiometer A21-R20 will required approximately 9 to 11 turns
CCW before the sine wave reaches the 13 VP area.
4. Performance of the DMS-D power supply calibration may be performed with the front panel assembly extended or
removed. If removed, a shorting cable must be connected between the front panel and the case or power supply
chassis.
5.
If a point is reached in the DMS-D power supply calibration, where the voltage outputs will not respond to any
potentiometer adjustment, return all potentiometer to the center of their adjustments momentarily remove power and
restart test.
6. During performance of the HORIZ WIRE SIM calibration, the operator should be cautious to observe that the reading is
being taken on the proper cards A typical operator error occurs when the TP's switch from card 1A5 to 1A6.
7. Due to the sensitivity of the calibration at step 97, it is recommended that the operator not make any adjustment if the
reading is within tolerance. (Do not adjust for nominal).
3-76