HP 8568B manual Video Processor Adjustments MHz Bandwidth Filter Adjustments

3

Adjustments

Introduction

Warning

The procedures in this section are for the adjustment of the instrument’s electrical performance characteristics.

The procedures require access to the interior of the instrument and therefore should only be performed by qualified service personnel. Refer to Safety Considerations in this introduction.

1. Low Voltage Power Supply Adjustments . . . . . . . . . . . . . . . . . . . . . .3-10 2. High Voltage Adjustment (SN 3001A and Below) . . . . . . . . . . . . . 3-10

2. High Voltage Adjustment (SN 3004A and Above) . . . . . . . . . . . . .3-10

3.Preliminary Display Adjustment (SN 3001A and Below) . . . . . .3-10

3.Preliminary Display Adjustment (SN 3004A and Above) . . . . . 3-10

4. Final Display Adjustments(SN 3001A and Below) . . . . . . . . . . . . .3-10

4. Final Display Adjustments(SN 3004A and Above) . . . . . . . . . . . . 3-10 5. Log Amplifier Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10

6. Video Processor Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

7. 3 MHz Bandwidth Filter Adjustments . . . . . . . . . . . . . . . . . . . . . . . . .3-10

8. 21.4 MHz Bandwidth Filter Adjustments . . . . . . . . . . . . . . . . . . . . . .3-10 9. 3 dB Bandwidth Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10 10. Step Gain and 18.4 MHz Local Oscillator Adjustments . . . . . . 3-10 11. Down/Up Converter Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10 12. Time Base Adjustment (SN 2840A and Below) . . . . . . . . . . . . . . 3-10

12. Time Base Adjustment (SN 2848A and Above) . . . . . . . . . . . . . . 3-10

13. 20 MHz Reference Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10

14. 249 MHz Phase Lock Oscillator Adjustments . . . . . . . . . . . . . . . . 3-10

15. 275 MHz Phase Lock Oscillator Adjustments . . . . . . . . . . . . . . . . 3-10 16. Second IF Amplifier and Third Converter Adjustments . . . . . 3-10

17. Pilot Second IF Amplifier Adjustments . . . . . . . . . . . . . . . . . . . . . . 3-10 18. Frequency Control Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10

19. Second Converter Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10 20. 50 MHz Voltage-Tuned Oscillator Adjustments . . . . . . . . . . . . . . .3-10

21. Slope Compensation Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10

22. Comb Generator Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10 23. Down/Up Converter Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10 24. Track and Hold Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10

25. Digital Storage Display Adjustments . . . . . . . . . . . . . . . . . . . . . . . . .3-10

The adjustment procedures should not be performed as routine maintenance, but only when Performance Tests cannot meet specifications. Before attempting any adjustment, allow the instrument to warm up for one hour. ‘lhble 3-1 is a cross reference of Function Adjusted to the related Adjustment procedure. Table 3-2 lists all adjustable components by name, reference designator, and function.

Adjustments 3-1