Tektronix DCM300, Technical Reference

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TAS 200 Series Adjustment Procedures
Handheld and Benchtop Instruments Basic Service
39
Trigger Adjustments
To locate the adjustments for the following procedures, refer to Figures 8 and 10.
The Main board occupies the bottom-right side of the instrument.
Use the following procedure to adjust the trigger DC offset.
1. Set up the oscilloscope as follows:
CH 1 (CH 2) VERTICAL POSITION Midrange
VERTICAL MODE CH1 (CH2)
CH 1 (CH 2) VOLTS/DIV 10 mV
CH 1 (CH 2) VARIABLE CAL
CH 1 (CH 2) AC-DC AC
HORIZONTAL SEC/DIV 1 ms
TRIGGER COUPLING AC
TRIGGER SOURCE CH 1 (CH 2)
2. Connect a 50 kHz sine wave to the CH 1 (CH 2) input. Adjust the generator
output to produce a waveform eight divisions in amplitude on the display.
3. Rotate the TRIGGER LEVEL control to set the trigger point at the center of
the signal swing.
4. Alternate the TRIGGER COUPLING control between the AC and DC
positions. Adjust VR110 (VR210) until the oscilloscope triggers at the same
amplitude for both switch positions. See Figure 8 for the adjustment
location.
5. Set the VERTICAL MODE and TRIGGER SOURCE to CH2 and repeat
steps 2 through 4 for channel 2.
Use the following procedure to adjust the trigger slope balance.
1. Set up the oscilloscope as follows:
VERTICAL MODE CH1
CH 1 AC-DC AC
CH 1 GND In
HORIZONTAL SEC/DIV 1 ms
Trigger DC Offset
Trigger Slope Balance