Chapter 1 Performance Tests

Test 2: Trigger Level (HP 53131A/132A Only)

7

In the Counter’s Channel 1 Trigger/Sensitivity menu, change the

 

 

SLOPE to NEG.

 

8

Set the HP 3325B DC OFFSET to +60 mV.

1

 

 

9

On the Counter, press Run key.

 

10

Now, decrement the offset on the HP 3325B by −1 mV until the

 

 

Counter’s Gate annunciator flashes and continue decrementing

 

 

 

 

until the Counter displays a stable reading of approximately

 

1 MHz.

 

Observe the offset value on the display of the HP 3325B.

 

Record the value__________ mV.

11

Add the lower peak voltage (−40mV) of the 80 mVp-p signal to the

 

offset value in step 10 (for example, 21 mV − 40 mV = −19 mv.)

 

This result is the lower hysteresis level.

 

Record the lower hysteresis level __________ mV.

12

Now, add the upper hysteresis value (recorded in step 6) and

 

lower hysteresis value (recorded in step 11).

 

This is the trigger level; it should be 0.0 V ±15 mV.

13

Record the trigger level value in the appropriate place in the

 

Performance Test Record (Test 2, Line 1).

14

Repeat steps 1 through 13 for Channel 2.

15

Record the trigger level value in the appropriate place in the

 

Performance Test Record (Test 2, Line 2).

16

Disconnect the test setup.

Assembly-Level Service Guide

1-21