Tektronix 744A User Manual

Page of 294
TDS 684A, TDS 744A, & TDS 784A Service Manual
4–15
Performance Tests
This section contains a collection of procedures for checking that the TDS 684A
and 7XXA Digitizing Oscilloscopes perform as warranted.
The procedures are arranged in four logical groupings: Signal Acquisition System
Check
s, Time Base System Checks, Triggering System Checks, and Output Ports
Checks
. They check all the characteristics that are designated as checked in
Specifications. (The characteristics that are checked appear in boldface type
under Warranted Characteristics in Specifications.)
STOP. These procedures extend the confidence level provided by the basic
procedures described on page 4–5. The basic procedures should be done first,
then these procedures performed if desired.
Prerequisites
The tests in this section comprise an extensive, valid confirmation of perform-
ance and functionality when the following requirements are met:
H The cabinet must be installed on the Digitizing Oscilloscope.
H You must have performed and passed the procedures under Self Tests, found
on page 4–5, and those under Functional Tests, found on page 4–7.
H A signal-path compensation must have been done within the recommended
calibration interval and at a temperature within 
±
5
_ C of the present
operating temperature. (If at the time you did the prerequisite Self Tests, the
temperature was within the limits just stated, consider this prerequisite met.)
H The Digitizing Oscilloscope must have been last adjusted at an ambient
temperature between +20
_ C and +30_ C, must have been operating for a
warm-up period of at least 20 minutes, and must be operating at an ambient
temperature between +4
_ C and either +45_ C for the TDS 684A or +50_ C
for the TDS 7XXA. (The warm-up requirement is usually met in the course
of meeting the first prerequisite listed above.)