HP 1740A - Accuracy Checks and Basic Displays

Operation
OVERSHOOT
CORRECT
UNDERSHOOT
1740A-003
Figure 3-2. Probe Compensation
wave amplitude should be five major divisions within
4%. For complete calibration check, refer to Section V.
3-11. Perform timing accuracy check as follows:
a. Apply an accurate calibration signal (such as
from HP Model 226A Time-mark Generator) to the
channel A INPUT @ connector.
b. Set controls to the positions indicated in the
turn-on procedure except for MAIN TIME/DIV which
should be adjusted to 0.5 uSEC/div.
c. Set marker on graticule line at far left with
horizontal position control. Markers should line up ap-
Model 1740A
proximately with each graticule line across the CRT.
The marker on the far right-hand side should be with-
in 2 mm of the graticule line.
3-12. TRIGGER SELECTION TABLE.
Table 3-1 will aid in determining the best trigger
mode for various signal conditions.
3-13. OBTAINING BASIC DISPLAYS.
3-14. These procedures will aid the operator in
becoming familiar with the operation of the Model
1740A so commonly used displays can be obtained.
Before performing the procedures, complete the turn-
on procedure and adjust the following controls:
Channel A TRIGGER................ A
Channel A coupling................ DC
Channel A VOLTS/DIV @ .......... 0.05
MAIN TIME/DIV @ .......... 0.5 mSEC
DELAY @ .................0645 fully CCW
3-15. NORMAL SWEEP DISPLAY.
a. Connect a Model 10006D probe to channel A
INPUT C21) connector, CAL 1 V ® output, and ground
post @.
Table 3-1. Display and Trigger Selection Table
SIGNAL CONDITIONS
I. Single Signals
Applied to
Channel A or B
A or B
II. Time Related Signals ALT
Applied to
Channels A & B CHOP
A+B (A—B)
III. Nontime Related Signals
Applied to
Channels A& B
Assume time related signal applied.
ALT
7 Time relation displayed.
No time relation displayed.
' If COMP is selected in CHOP, switching
overrides and selects A.
Signal is only displayed on one channel.
3-2
ALT or CHOP®
COMP EXT
OK OK!
NG OK!
NG! OK?
OK OK
NG NG
Triggers on algebraic sum or difference of
signals.
OK Useable trigger mode.
Good trigger mode.
Best trigger mode.
NG _ Unuseable trigger mode.
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