HP 54645A, User'S And Service Manual

Page: 211 / 301

To verify horizontal
∆
t and 1/
∆
t accuracy
In this test, you verify the horizontal
∆
t and 1/
∆
t accuracy by measuring the
output of a time mark generator with the oscilloscope.
Test limits:
±
0.01%
±
0.2% of full scale
±
40 ps (same channel)
Table 7-8 Equipment Required
Equipment Critical specifications Recommended Model/Part
Time marker generator Stability 5 ppm after 1/2 hour TG 501A and TM 503B
Cable BNC, 3 feet HP 10503A
Termination 50
Ω
, BNC connectors (m) and (f) HP 11048C
1
Connect the time mark generator to channel 1 using the 50-
Ω
feedthrough at the oscilloscope input. Then, set the time mark
generator for 0.1-ms markers.
Channel 1 is labeled "1" on HP 54645A and "A1" on HP 54645D.
2
Set up the oscilloscope.
a
Press
Setup
, then press the
Default Setup
softkey.
a
Press
Display
, then press the
Vectors Off
softkey.
c
Press
Autoscale
.
d
Set the time base to 20
µ
s/div.
e
Press
Main/Delayed
, then press the
Time Ref Left
softkey.
f
Adjust the trigger level to obtain a stable display.
3
Press
Time
, then press the
Freq
and
Period
softkeys.
You should measure the following:
Frequency 10 kHz, test limits are 9.96 kHz to 10.04 kHz.
Period 100
µ
s, test limits are 99.59
µ
s to 100.41
µ
s.
If the measurements are not within the test limits, see "Troubleshooting the
Oscilloscope."
4
Change the time mark generator to 1
µ
s, and change the time base to
200 ns/div. Adjust the trigger level to obtain a stable display.
Testing, Adjusting, and Troubleshooting
To verify horizontal
∆
t and 1/
∆
t accuracy
7-22