Tektronix 544 - Adjust VERT GAIN (Vertical Amplifier Gain) R1017- Vertical Amplifier; Check Common-Mode Rejection- Vertical Amplifier; Adjust TRIGGER LEVEL CENTERING R225 and TRIGGER SENS (Trigger Sensitivity) R245- Coarse Adjustment- Sweep Trigger

Calibration— Type 544/RM544
h. Set the Type TU-7 Test Function switch to Common
Mode.
i. Adjust the VERT DC BAL control R1044 (see Fig. 5-4)
to position the trace to the center of the graticule.
10. Adjust VERT GAIN (Vertical Amplifier Gain)
R1017— Vertical Amplifier
a. Set the Type TU-7 Test Function switch to the Gain
Set position.
b. Connect a coaxial cable between the Type TU-7 Ext
Input connector and the oscilloscope CAL OUT
connector.
c. Set the AMPLITUDE CALIBRATOR switch to 100
VOLTS.
d Pull the TRIGGERING LEVEL control outward for XI0
ronge increase and rotate the control fully clock
wise to free run the time base.
e. Adjust the VERT GAIN control R1017 (see Fig. 5-4) so
the display vertical deflection is exactly 4 cm in
amplitude.
11. Check Common-Mode Rejection— Vertical
Amplifier
a. Set the AMPLITUDE CALIBRATOR switch to 1 VOLT.
b. Set the TU-7 Test Function switch to Common Mode.
c. Set the TIME/CM switch to .5 mSEC.
d. Note the amplitude of the calibrator waveform. The
amplitude of the waveform should not be moro than
3 mm maximum.
12. Adjust TRIGGER LEVEL CENTERING R225 and
TRIGGER SENS (Trigger Sensitivity) R245— Coarse
Adjustment— Sweep Trigger
a. Set the AMPLITUDE CALIBRATOR switch to OFF.
b. Insert the BNC T connector (item 13) between the
AMPLITUDE CALIBRATOR connector and the coax
cable.
c. Connect another coaxial coble from the 'T' connector
to the TRIGGER INPUT connector. (The CAL OUT
connector should now be connected to the Ext Input
connector on the Type TU-7 and to the TRIGGER
INPUT connector on the oscilloscope.)
d. Set the TU-7 front-panel controls as follows:
VARIABLE Fully cw
POSITION Centered
TEST FUNCTION Low Load
e. Set the MODE switch to TRIG, and the TRIGGERING
LEVEL control to 0 (knob pulled out). Check that the
COUPLING switch is set to AC and the SOURCE
switch is set to NORM. (Table 5-4 lists the remaining
front-panel control settings up to this point in the
procedure.)
TABLE 5-4
INTENSITY
FOCUS
ASTIGMATISM
SCALE ILLUM
TRIGGERING LEVEL Knob
TRIGGERING-
SLOPE
VARIABLE (TIME/CM)
TIME/CM
HORIZONTAL DISPLAY
Single Sweep Switch
HORIZONTAL POSITION
VERNIER (HORIZONTAL
POSITION)
= 3
=:5
2:5
2: 8
Pulled out
+
CALIBRATED
.5 mSEC
NORMAL
NORMAL
About —10° from centor
Midrange
f. Locate the junction of R217, C218, and R218 (sec Fig.
5-5). Connect a short jumper clip lead (item 11) be
tween the junction and ground. This jumper disables
the TRIGGERING LEVEL control.
TRIGGER
LEVEL CENTERING
RJJS
IN I TRIG
OC LEVEL
R709
Ground
R 21 7/C 2 I8 /R JI8 Jumper
(Junction ol SW 215I Clip
- ________________load
Fig. 5-5. Trigger dip-load connection*, ad|u>tmonl and tod point
locations luppor right corner viow l.
g. Rotate the TRIGGER LEVEL CENTERING R225 and
TRIG SENS R245 controls (sec Fig. 5-5) fully clockwise.
h. Rotate the TRIGGER LEVEL CENTERING R225 control
slowly counterclockwise until a steady trace appears.
Do not turn the control any further counterclockwise
than the point where the steady bright trace was first
obtoined.
NOTE
If a steady trace appears regardless of the setting
of the TRIGGER LEVEL CENTERING R225 control, ro
tate the TRIG SENS R245 control a few degrees
5-6