HP 8568B manual Focus and Intensity Adjustments, Press @%KiZi@, Press Display

Focus and Intensity Adjustments

2. High-Voltage Adjustment (SN 3001A and Below)

If the calibration factor calculated in step 8 is 0.00099, and AlA3Tl is labeled for -3875 V, then adjust AlA6R32 HV ADJ for a DVM indication of:

0.00099 x (-3875 V) = -3.836 V dc

16.With the front-panel INTENSITY control fully counterclockwise, wait approximately 30 minutes to allow the high-voltage supply to stabilize and the CRT to normalize. This sofl turn-on will extend CRT life expectancy, particularly if a new CRT has just been installed.

17.Readjust AlA6R32 HV ADJ for a DVM indication equal to the voltage determined in step 15.

18.If a new CRT has just been installed do the following:

a.Set the front-panel INTENSITY control so the CRT trace is barely visible.

b.Wait an additional 30 minutes for the CRT to normalize.

c.Readjust AlA6R32 HV ADJ for a DVM indication equal to the voltage determined in step 15.

19.Set the LINE switch to STANDBY. Remove the ac line cord from each instrument section.

20.Wait at least one minute for the MAINS power-on indicator AlA8DSl (red LED) to go out completely before proceeding.

21.Disconnect the high-voltage probe from AlA3TP3.

22.Remove the A3A2 Intensity Control Assembly from the IF-Display Section and install in its place the Display Adjustment Board,

HP part number 85662-60088. Set the switch on the Display Adjustment Board in the “down” position. (This applies approximately +2.7 V dc to the front-panel INTENSITY control.)

23.Connect a calibrated 1O:l divider probe to the oscilloscope Channel 1 input.

24.On the oscilloscope, press (RECALL) (CLEAR) to perform a soft reset.

25.On the oscilloscope, press CCHAN], more preset probe , select channel 1, and use the front-panel knob to select a 1O:l probe.

26.Set the oscilloscope controls as follows:

Press [CHAN):

Channel 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . on amplitude scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .lO.OV/div offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..6O.OOOOV coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..dc

Press @%KiZi@:

time scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..50~s/div Press ITRIG):

EDGE TRIGGER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . auto, edge source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..l level . . . . . . . . . . . . . . . . . . . . . . . . . .75.0000 V, rising edge

Press [DISPLAY):

connect dots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..on

Adjustments 3-33