Tektronix Type 82 PLUG-IN Instruction Manual page 17

Operating Instruction—Type 82
VARIABLE VOLTS/CM control is rotated or if the A POLAR!-
TY/B POLARITY switches are operated at this trace position.
When both the channel A X1 and X10 POSITION RANGE
adjustments are correctly adjusted, a balanced positioning
range above and below the graticule center is maintained.
To make the adjustments, proceed as follows:
1, Set the front-panel controls the same as outlined in steps
1 and 2 in the X1 GAIN Adjustments procedure except that
the A VERTICAL POSITION control must be set so the white
dot is at 0° or 12 o'clock position. (This is the electrical
center of the control as set at the factory.) Do not apply any
signal to the Type 82.
2. As a preliminary setting, adjust the channel A X1 POSI-
TION RANGE control to the point where there is no trace
shift on the screen as the channel A VARIABLE VOLTS/CM
3. For the final setting, place the GAIN switch to the X10
position and readjust the A X1 POSITION RANGE control
for minimum trace shift as the channel A VARIABLE
VOLTS/CM control is rotated.
NOTE
When performing step 3, leave the A VERTICAL
POSITION control at 0° and use the channel A
X10 POSITION RANGE control to keep the trace
on the crt while adjusting the channel A X1
4. Adjust the channel A X10 POSITION RANGE contro! to
position the trace to the graticule X-axis centerline.
After adjusting the channel A X1 POSITION
RANGE and X10 POSITION RANGE controls
properly, trace shift is minimum and dc balance
is correct while the channel A VERTICAL POSI-
TION control remains at 0°. If the VERTICAL
POSITION control is moved away from 0°, as it
will be during normal operation, dc imbalance
and an increased amount of trace shift will occur
when operating the channel A VARIABLE
VOLTS/CM control and/or A POLARITY switch.
Channel B X1 POSITION RANGE and
X10 POSITION RANGE Adjustments
The purpose of these adjustments is the same as those for
1. To make the adjustments set the Type 82 front-panel
controls for channel B to these settings.
AC-DC-GND DC
V/CM J
VARIABLE VOLTS/CM CAL.
B POLARITY NORM.
VERTICAL POSITION 0°
GAIN Xl
MODE B ONLY
2. Set the oscilloscope sweeep rate and triggering controls
3. As a preliminary setting, adjust the channel B X1 POSI-
TION RANGE control to the point where there is no trace
shift on the screen as the channel B VARIABLE VOLTS/CM
control is rotated.
4. For a final setting, set the GAIN switch to the X10 posi-
tion and readjust the B X1 POSITION RANGE control for
minimum trace shift as the channel B VARIABLE VOLTS/CM
In step 4 of this procedure, ieave the B VERTICAL
POSITION control at 0° and use the channel B
X10 POSITION RANGE control to keep the trace
on the crt while adjusting the channel B XI]
POSITION control,
5. Adjust the channel B X10 POSITION RANGE control to
position the trace to the graticule centerline.
IMPORTANT
After adjusting the channel B X1 POSITION
RANGE and X10 POSITION RANGE controls
is correct while the channel B VERTICAL POSI-
TION control remains at O°. If the VERTICAL
POSITION control is moved away from 0°, as it
will be during normal operation, greater trace
shift due to dc imbalance will occur when opera-
ting the channel B VARIABLE VOLTS/CM control
and/or B POLARITY switch.