Tektronix 422, Instruction Manual

Page: 118 / 213

Performance Check/Calibration—Type 422 AC-DC
b. Connect the high-frequency constant-amplitude sine-
wave generator (Type 191) to the INPUT 2 connector
through the GR to BNC adapter, 18-inch 50-ohm BNC
cable and the 50-ohm BNC termination.
c. Set the constant-amplitude generator for a four-
division display, centered on the graticule, at its reference
frequency (50 kilohertz).
d. W ithout changing the output amplitude, increase the
output frequency of the constant-amplitude generator until
the display is reduced to 2.8 divisions (—3 dB point).
e. CHECK—Output frequency o f generator must be 15
megahertz or higher.
f. Set the vertical Mode switch to CH 2.
g. Disconnect the BNC termination from the INPUT 1
connector and re-connect it to the INPUT 2 connector.
h. Set the constant-amplitude generator fo r a four divi­
sion display, centered on the graticule, at its reference fre­
quency (50 kilohertz).
i. W ithout changing the o utput amplitude, increase the
output frequency o f the constant-amplitude generator until
the display is reduced to 2.8 divisions (—3 dB point).
j. CHECK—Output frequency of generator must be 15
megahertz or higher.
29. Check Channel 2 X I 0 Gain Upper Vertical
Bandwidth
a. Set the Channel 2 Input Coupling switch to AC.
b. Pull the X10 GAIN AC switch.
c. Set the constant-amplitude generator for a four-
division display, centered on the graticule, at its reference
frequency (50 kilohertz).
d. W ithout changing the o utput amplitude, increase the
output frequency of the constant-amplitude generator until
the display is reduced to 2.8 divisions (—3 dB point).
e. CHECK—Output frequency of generator must be five
megahertz or higher.
30. Check Common-Mode Rejection Ratio
a. Connect the high-frequency sine-wave generator to
the INPUT 1 and 2 connectors through the GR to BNC
adapter, 18-inch 50-ohm BNC cable, 50-ohm BNC termina­
tion and the dual-input coupler.
b. Push in the X10 GAIN AC switch.
c. Set the sine-wave generator fo r an eight-division dis­
play at 50 kilohertz.
d. Change the follow ing control settings:
Vertical Mode A LG ADD
INVERT Pulled out
e. CHECK—CRT display fo r 0.1 division deflection, or
less (common-mode rejection ratio o f 100:1 or greater).
f. Disconnect all test equipment.
31. Check AC-Coupled Lower Vertical Bandwidth
Limit
a. Change the follow ing control settings:
CH 1 and 2 Input Coupling AC
Vertical Mode CH 1
INVERT Pushed in
T IM E /D IV ,5 s
b. Connect the low-frequency constant-amplitude sine-
wave generator to the INPUT 1 connector through the BNC
to dual binding post adapter, 42-inch 50-ohm BNC cable
and the 50-ohm BNC termination.
c. Set the low-frequency generator fo r a four-division
display, centered on the graticule, at a reference frequency
of one kilohertz.
d. W ithout changing the output amplitude, reduce the
output frequency o f the generator to tw o hertz.
e. CHECK—CRT display 2.8 divisions, or greater, in
amplitude (not more than —3 dB).
f. Set the vertical Mode switch to CH 2.
g. Disconnect the 50-ohm termination from the INPUT
1 connector and reconnect it to the INPUT 2 connector.
h. Set the low-frequency generator fo r a four-division
display, centered on the graticule, at a reference frequency
o f one kilohertz.
i. W ithout changing the output amplitude, reduce the
output frequency o f the generator to two hertz.
j. CHECK—CRT display 2.8 divisions, or greater, in
amplitude (not more th a n —3 dB ).
k. Pull the X 10 GAIN AC switch.
l
. Set the low-frequency generator fo r a four-division
display, centered on the graticule, at a reference frequency
o f one kilohertz.
m. W ithout changing the output amplitude, reduce the
output frequency o f the generator to five hertz.
n. CHECK—CRT display 2.8 divisions or greater in
amplitude (not more than —3 dB).