3.Preliminary Display Adjustments (SN 3004A and Above)

29.Set the oscilloscope controls as follows:

Press (CHAN]:

 

 

 

 

 

 

 

 

 

 

 

Channel 1

.

.

.

.

.

.

.

.

.

.

on

amplitude scale . . . . . . .

 

 

.8.00

V/div

Press @KiX-].

 

 

 

 

 

 

 

 

 

 

 

30.Adjust the spectrum analyzer’s front-panel INTENSITY control for 50V peak-to-peak (8 divisions) as indicated on the oscilloscope. See Figure 3-29.

hf r u n n i n g

 

1.

 

- 1 2 5 . 0 0 0 ns

1 2 5 . 0 0 0 ns

375.000~"s

 

5 0 . 0 ns/div

 

1 f 50.00 v

Figure 3-29. 5OV,., Signal

31.Adjust AlA2R308 HF GAIN and AlA2C307 for minimum overshoot on rise and minimum rise and fall times of the pulse waveform.

32.Use the oscilloscope Intav) markers to measure the risetime, falltime, and percent overshoot of the pulse waveform. Rise and falltimes should be less than 50 ns and 90 ns respectively. Overshoot on the rise should be less than 5% (approximately 0.4 divisions).

33.Set the spectrum analyzer’s LINE switch to STANDBY and reconnect the cable to AlA2J5.

34.Disconnect the oscilloscope channel 1 probe from the spectrum analyzer. Remove the Display Adjustment PC board from the A3A2 slot, and reinstall the A3A2 Intensity Control Assembly. Replace the A3 Section cover and cables.

35.Reconnect the black connector with three wires (8, 98, and 96) to AlA2J5, and set AlA2R319 INT GAIN approximately two-thirds clockwise.

36.Perform Adjustment Procedure 4 Final Display Adjustment (SN 3004A and Above).

3-58 Adjustments