Tektronix MTG100, MTG300, Service Manual

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Adjustment Procedures
MTG100 & MTG300 MPEG Generator Service Manual
5Ć3
To avoid serious injury, do not touch exposed connections or
components when operating the instrument with the protective enclosure
removed. Dangerous potentials exist at several points within the MPEG
generator.
Initial Setups.
Frequency counter:
Function Freq A . . . . . . . . . . . . . . . . .
Gate Time > 0.2 s . . . . . . . . . . . . . . . .
Procedure.
1. Connect the power cord to the MPEG generator, and power on the instru-
ment. Remember to allow at least 20 minutes for the instrument to warm-up
before making any adjustment.
2. Connect the P6139A probe to the frequency counter input (INPUT A).
3. Locate the test point TP3714 and U3712 on the A10 Main board. See
Figure 5-1.
4. Adjust the clock frequency:
a. Attach the probe tip to the TP3714.
b. Turn the adjustment pod on U3712 clockwise or counterclockwise so
that the frequency at the test point is in the range of 26.999984 MHz to
27.000016 MHz (< 0.6 ppm).
Adjustment