Tektronix VITS100 Power Supply Adjustment, Genlock Adjustments

Adjustment Procedures
VITS100 NTSC VITS Inserter Instruction Manual 6–5
Use this step to adjust the +5 V Adjust, R170, which serves as the reference for
all other power supplies in the VITS inserter.
NOTE. This adjustment affects all adjustments in the VITS inserter. Therefore, if
the +5 V supply is within tolerance, do not reset R170 unless you are prepared to
perform the complete Adjustment Procedure.
1. Connect a multimeter to TP2 (test point 2) and TP7 (ground) on the circuit
board. See Figure 6–1 for the location of the test points.
2. Adjust R170 for 5.0 V.
3. Check power supply tolerances as shown in Table 6–2.
Table 6–2: Power Supply Tolerances
Power Supply Voltage Range Test Point
+5 V +4.8 V to +5.2 V TP2
–5.2 V –4.9 V to +5.5 V TP1
+12 V +11.88 V to 12.12 V TP6
–12 V –11.88 V to 12.12 V TP5
Ground TP7
Adjust genlock performance with the following steps.
1. Connect the Test Oscilloscope X10 probe to U44 Pin 18.
2. Select the NTC7 Composite signal from the test signal generator.
3. Adjust R40, Horizontal Osc, for a clean 6.0 V trace.
4. Check that both the Front Panel UNLOCK and BYPASS light-emitting
diodes (LEDs) are off.
5. Connect a 75 W coaxial cable from the VITS inserter PROGRAM OUT to
the waveform/vector monitor Ch A input. Terminate the remaining side of
the loop-through input with a 75 W end-line terminator. See Figure 6–2.
Power Supply Adjustment
Genlock Adjustments