Adjust Channel 2 Invert Balance; Adjust Vertical G Ain; Check Deflection Accuracy And Volts/Div Variable Range; Check Input Coupling - Tektronix 2205 Service Manual

g. Return the CH 1 VOLTS/DIV Variable control to
the CAL detent
3. Adjust Channel 2 Invert Balance (R84)
a. Position the trace on the center horizontal
graticule line using the Channel 2 POSITION control.
b. Set Vertical MODE switch to CH 2 INVERT.
c. ADJUST—CH 2 Invert Bal (R84) to set the trace
to the center horizontal graticule line.
d. Set Vertical MODE switch to NORM.
e. Repeat parts a through d until there is no trace
shift when switching from NORM to CH 2 INVERT.
4. Adjust Vertical Gain (R145 and R195)
a. Set:
Vertical MODE
CH 1 VOLTS/DIV Variable
AC-GND-DC (both)
Trigger SOURCE
b. Connect a 20-mV, standard-amplitude signal
from the calibration generator via a 50-D coaxial
cable to the CH 1 X input connector.
or
c. Center the display within the graticule using
the CH 1 POSITION control.
d. ADJUST-CH 1 Gain (R145) for an exact 4 -
division display.
e. Move the test-signal cable from the CH I
input connector to the CH 2 OR Y input connector.
f. Set the Vertical MODE switch to CH 2.
g. Center the display within the graticule using
the CH 2 POSITION control.
h. ADJUST-CH 2 Gain (R195) for an exact 4 -
division display.
i. Repeat parts b through h until the gain of the
two channels is identical.
5. Check Deflection Accuracy and VOLTS/DIV
Variable Range
a. CHECK—Deflection accuracy is within the limits
given in Table 5-3 for each CH 1 VOLTS/DIV switch
setting and corresponding standard-amplitude sig­
nal. When at the 20-mV VOLTS/DIV switch setting,
rotate the CH 1 VOLTS/DIV Variable control fully
counterclockwise and CHECK that the display
decreases to two divisions or less. Then return the
CH 1 VOLTS/DIV Variable control to the CAL detent
and continue with the 50-mV check.
b. Move the cable from the CH 1 OR X input con­
nector to the CH 2 OR Y input connector. Set the
Vertical MODE switch to CH 2.
c. Repeat part b using the Channel 2 controls.
VOLTS/DIV
Switch
Setting
CH 1, NORM
CAL detent
DC
VERT MODE
... 0.5 V ..

6. Check Input Coupling

X
or
a. Set the AC-GND-DC switches (both channels)
to GND.
b. Position the trace on the center horizontal
graticule line using the CH 2 POSITION control.
c. Change the generator output to 50 mV.
d. Set the Channel 2 AC-GND-DC switch to AC.
e.
center horizontal graticule line.
f. Set the Channel 2 AC-GND-DC switch to DC.
g. CHECK— The display is ground referenced on
the center horizontal graticule line.
h. Move the test-signal cable from the CH 2 OR Y
input connector to the CH 1 OR X input connector,
Adjustment Procedure—2205 Service
Table 5-3
Deflection Accuracy Limits
STANDARD
Amplitude
Signal
20 mV
5 mV
50 mV
10 mV
20 mV 0.1 V
0.2 V
50 mV
0.1 V 0.5 V
1 V
0.2 V
2 V
1 V 5 V
2 V 10 V
5 V 20 V
CHECK— The display is centered about the
ACCURACY
Limits
(Divisions)
3.88 to 4.12
4.85 to 5.15
4.85 to 5.15
3.88 to 4.12
4.85 to 5.15
4.85 to 5.15
3.88 to 4.12
4.85 to 5.15
4.85 to 5.15
3,88 to 4.12
5-7