Adjust High-Frequency Compensation - Tektronix 323 Series Instruction Manual

b. Disconnect the output of the BNC termination from the
VERT INPUT connector and reconnect it to the EXT TRIG OR
HORIZ INPUT connector.
c. Set the square-wave generator for a five-division dis­
play on the test oscilloscope at one kilohertz.
d. CHECK—Test oscilloscope display for optimum square-
wave response (optimum square corner and flat top).
e. ADJUST— C206 (see Fig. 6-11C) for optimum square-
wave response.
f. Disconnect all test equipment.

27. Adjust High-Frequency Compensation

a. Change the following control settings:
VOLTS/DIV
Trig/Horiz Coupling
TIME/DIV
X 10 HORIZ MAG
b. Connect the square-wave generator fast-rise +
put connector to the VERT INPUT connector through the GR
to BNC adapter, 42-inch 50-ohm BNC cable, 10X BNC
attenuator and the 50-ohm BNC termination.
c. Set the square-wave generator for a four-division dis­
play at 100 kilohertz.
d. Move the leading edge of the square wave onto the
viewing area with the horizontal POSITION control.
e. Set the test oscilloscope for a vertical deflection fac­
tor of one volt/division (10 volts/division at 10X probe tip)
at a sweep rate of two microseconds/division. Adjust the
triggering controls when necessary to provide a stable dis­
play.
f. Connect the 10X probe tip to the collector of Q163
(case of Q163; see Fig. 6-12B). Be sure the probe is com­
pensated.
g. CHECK—Test oscilloscope display for flat top on
square wave similar to Fig. 6-12A.
h. ADJUST—Cl 60 (see Fig. 6-12B) for optimum flat top
on square wave.
i. Connect the 10X probe tip to the collector of Q173
(case of Q173; see Fig. 6-12B).
j. CHECK—Test oscilloscope display for flat bottom on
square wave similar to Fig. 6-12A.
k. ADJUST—C l70 (see Fig. 6-12B) for optimum flat bottom
on square wave.
. Install the calibration shield on the Type 323.
l
m. CHECK—Type 323 CRT display for optimum square
corner similar to Fig. 6-12C.
o
.01
INT TRIG AC
5 /xs
Pulled out
out­
n. ADJUST— Cl 60 and Cl 70 about the same amount in
the same direction for optimum square corner on the CRT
display.
o. Disconnect all test equipment and remove the cali­
bration shield.
Fig. 6 -1 2 . (A ) Typical oscilloscope d ispla y when adjusting
frequency com pensation, (B) location o f high-frequency compensation
test points and adjustments (M a in b o a rd ), (C) typica l CRT display
showing correct high-frequency com pensation.
Calibration— Type 323
high-
6-17