Tektronix 7623, Instruction Manual

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Calibration —7623/R7623 Service
f. CHECK-Output frequency must be 100 megahertz
or higher.
g. Remove the calibration fixture from the right vertical
compartment and install it in the left vertical compartment
(leave signal connected).
h. Set the VERT MODE switch to LEFT.
i. Repeat parts d through f. Actual frequency (right
vertical), 100 megahertz or higher.
j. Disconnect all test equipment (leave plug-in units
installed).
17. Check Vertical Amplifier Isolation
a. Remove the mainframe standardizer calibration fix­
ture from the right vertical compartment and install the
7A15A in this compartment.
b. Set the 7A15A for a deflection factor of 0.1
volt/di vision.
c. Connect the output of the high-frequency generator
to the input of the 7A15A.
d. Set the high-frequency generator for eight divisions
of deflection at 100 megahertz.
e. Set the VERT MODE switch to RIGHT.
f. CHECK-CRT display for not more than 0.1
division of 100 megahertz signal (channel isolation at least
100:1).
g. Remove the 7A15A from the left vertical compart­
ment and install it in the right vertical compartment (leave
signal connected).
h. Set the high-frequency generator for eight divisions
of deflection at 100 megahertz.
i. Set the VERT MODE switch to LEFT.
j. CHECK -CRT display for not more than 0.1
division of 100 megahertz signal.
k. Disconnect all test equipment.
18. Check ADD Operation
a. Install the other 7A15A in the left vertical compart­
ment.
b. Set both 7A15A units for a deflection factor of 0.2
volt/division.
c. Connect the 0.4 V Calibrator signal to the inputs of
the 7A15A units with the BNC to pin-jack cable and
dual-input coupler.
d. Set the 7B53A for auto, internal triggering at a sweep
rate of 0.5 millisecond/division.
e. Center the display with the left 7A15A Position
control and note the vertical deflection.
f. Set the VERT MODE switch to RIGHT.
g. Center the display with the right 7A15A Position
control and note the vertical deflection.
h. Set the VERT MODE switch to ADD.
i. CHECK—CRT display; vertical deflection should
approximately equal the algebraic sum of the deflection
noted in parts e and g of this step.
j. Disconnect the BNC to pin-jack cable and dual-input
coupler.
19. Check Alternate Operation
a. Set the VERT MODE switch to ALT.
b. Position the traces about two divisions apart.
c. Turn the 7B53A Time/Division switch throughout its
range.
d. CHECK—Trace alternates between the left and
right 7A15A units at all sweep rates. At faster sweep rates,
alternations will not be apparent; instead, the display
appears as two traces on the screen.
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