Tektronix 7B92 Instruction Manual page 41

Calibration-7B92 Service
g. INTERACTION-Repeat the adjustment of C443,
C414, and C449 (Calibration step 24) as necessary.
h. Change the following control settings:
TIME/DIV OR
DLY TIME
DL Y'D Time/Division
Main Triggering
LEVEL
1 tls
0.1 tls
Adjust for a stable
display
i. Rotate the DELAY TIME MULT dial to 1.00. If
necessary, further rotate the dial to start the delayed sweep
(lower trace) on the second 1 tls marker.
j. Note the exact DELAY TIME MULT dial setting.
k. Rotate the DELAY TIME MUL T dial exactly 8.00
divisions from the setting noted in part j.
I. CHECK-That the delayed sweep starts on the tenth
1 tls marker.
m. ADJUST -C414, Delaying One Microsecond Timing,
to start the delayed sweep trace on the tenth 1 tls marker.
26. Check/Adjust Delay Pickoff
TO
Bias (R364)
a. Set the time·mark generator for two·nanosecond
markers.
b. Change the following control settings:
DELAY TIME MULT
TIME/DIV OR
DLY TIME
DLY'D Time/Division
POSITION
ALT
Fully counterclockwise
.1 tls
2 ns (press in for DL Y'D
Sweep Display Mode)
Fully clockwise
(Press in)
c. Set the 7 A 19 Volts/Div switch for approximately two
divisions of display. Position the display as necessary.
d. Rotate the MAIN TRIGGERING LEVEL control to
trigger the display near the zero volt level. Do not change
this LEVEL control setting.
e. Disconnect the time·mark signal from the 7A19
Input.
4-20
Scans
bv
OutsouFce-Ont;ons
=>
f. Remove the 7A15A Amplifier unit from the Right
Vert compartment of the oscilloscope. Install the 7S12
TDR/Sampler (with S·l Sampling Head and S·52 Pulse
Generator Head) into the center two compartments of the
osci II oscope.
g. Connect the Pulse Output of the S·52 Pulse Genera·
tor Head to the 7 A 19 I nput with a SMA (3 mm)
male·to·BNC female adapter and a 42·inch BNC cable.
h. Set the 7A19 Volts/Div switch for approximately
two divisions of display.
i. CHECK-CRT display for leading edge of the pulse
between the sixth and seventh graticule lines.
j. ADJUST -R364, Delay Pickoff TD Bias, fully
counterclockwise. Then adjust R364 clockwise until the
leading edge of the pulse is between the sixth and seventh
graticule lines.
k. Remove the 7B92 and plug·in extender from the
oscilloscope, then install the 7B92 directly into the B
Horizontal compartment.
I. CHECK-CRT display for leading edge of the pulse
between the seventh and eighth graticule lines.
m. INTERACTION-If the requirements in step I can-
not be met, install the 7B92 and plug-in extender into the B
Horizontal compartment and repeat steps i through I. The
adjustment of R364, given in step j, may need to be varied
slightly to meet requirements given in step I.
27. Check/ Adjust High-Frequency Linearity
(C557, C565, C572)
a. Remove the 7 A 19 Amplifier unit and the 7B92 Time
Base unit from the oscilloscope.
b. Install the 7S11 Sampling unit (with Sl Sampling
Head) into the Left Vert compartment of the 7904
Oscilloscope.
c. Disconnect the BNC cables from connectors A 11 and
B 11 of the 067·0589-00 plug-in extender. Install the 7B92
and plug-in extender into the B Horizontal compartment of
the oscilloscope.
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