Check Sweep Jitter; Check Horizontal Amplifier Bandwidth; Check Amplifier Variable Range - Tektronix 7B70 Time Base Instruction Manual

Performance CheckICalibration-7B70 (SN B205000 and Up)
j. CHECK-Using the control settings in Table 5-4,
n. CH ECK-Using the control settings in Table 5-6,
check for stable triggering and a lit TRIG'D lamp for each check for stable triggering and a lit TRIG'D lamp for each
condition listed (see step 12a). condition listed (see step 12a).
TABLE 5 4 TABLE 5-6
AC LF REJ
1
E XT
1
30 kHz
1
7 5 m V
A C H F REJ
I
EXT
1
50 kHz
1
7 5 m V
7870
AC
AC HF REJ
D C
AC LF REJ
AC HF REJ
AC
AC HF REJ
D C
COUPLING
Sine-Wave Generator 7870
SOURCE
INT
INT
INT
I NT
I NT
EXT
EXT
EXT
AC
DC
AC LF REJ
-
A C L F REJ
I
EXT
1
200 MHz
1
3 7 5 m V
Frequency
Calibration Fixture
AC
DC
13. Check Sweep Jitter
I
Amplitude COLlPLlNG SOLIRCE Frequency
30 Hz
30 Hz
30 Hz
30 kHz
,
50 kHz
1
30Hz
1
30Hz
30 Hz
I NT
I NT
INT
a. Set the 7870 TIMEIDIV t o .02 microsecond, MAG-
NIFIER t o X10, and SOURCE to INT.
Amplitude
0.3 div
0.3 div
0.3 div
0.3 div
0.3 div
75 mV
75 mV
75 mV
EXT
EXT
k. Set the 7870 COUPLING t o DC and change the "T"
b. Set the 067-0532-01 Calibration Fixture t o 150 MHz
connector from the low-frequency generator t o the Type
and adjust the amplitude for a four division display.
191 signal generator output connector (using a GR t o BNC
adapter). Set the Type 191 frequency t o 20 MHz and adjust
the amplitude for 75 millivolts.
c. CHECK-For no more than 0.5 division (1 nano-
second) of jitter. Disregard any slow drift.
200 MHz
200 MHz
200 MHz
I. CHECK-Using the control settings in Table 5-5,
d. Disconnect the Calibration Fixture,
'7"
connector,
check for stable triggering and a lit TRIG'D lamp for each
and attenuator.
condition listed (see step 12a).
1.5 div
1.5 div
1.5 div
200 MHz
200 MHz
14. Check Horizontal Amplifier Bandwidth
375 mV
375 mV
TABLE 5-5
a. Reset the SOURCE t o EXT, COUPLING t o AC, and
DISPLAY MODE to AMPLIFIER. Connect a 1 kHz signal
from the low-frequency sine-wave generator through a 50 52
BNC cable to the EXT VOLTS IN connector, and adjust
the sine-wave generator amplitude for six horizontal divi-
7870
sions of display on the CRT (use the Position control as
Type 191
COUPLING
D C
AC
AC LF REJ
DC
AC
AC LF REJ
necessary
1.
Frequency
20 MHz
20 MHz
20 MHz
20 MHz
20 MHz
20 MHz
SOURCE
E XT
EXT
EXT
I NT
INT
I NT
b. CHECK-Reset the sine-wave generator t o 100 kHz
and check for a display amplitude of at least 4.2 divisions.
Amplitude
75 mV
75 mV
75 mV
0.3 div
0.3 div
0.3 div
15. Check Amplifier VARIABLE Range
a. Adjust the sine-wave generator for an eight division
horizontal display on the CRT. (The VARIABLE control
m. Set the 7870 COUPLING to AC, SOURCE to INT,
must be set fully clockwise.)
and change the
'7"
connector from the Type 191 signal
generator t o the 067-0532-01 Calibration Fixture output
connector. Set the Calibration Fixture frequency to b. CHECK-Rotate t h e VARIABLE control fully
200 MHz and adjust the amplitude for a a 1.5 division
counterclockwise and check for 0.8 division or less of hori-
display. zontal display.
Scans by ArtekMedia O 2006