Tektronix 2213, Instruction Manual

Page: 70 / 225

Adjustment Procedure— 2213 Service
NOTE
The following adjustm ent is only applicable to
instalm ents having the Current Lim it board (A 19).
d. ADJUST— Head Room Voltage Adjust (R952) for
+ 4 .3 V if your instrument contains the Current Limit board.
Adjust for 43 V if your instrument contains the
Preregulator board.
e. Disconnect the voltmeter leads.
f. Connect the digital voltmeter low lead to chassis
ground (TP501) and connect the volts lead to the —8.6 V
supply (TP500).
g. CHECK— Reading is —8.64 V to —8.56 V. If the
reading is within these limits, skip to part i.
h. ADJUST—The -8 .6 V Adj (R946) for -8 .6 V.
i. Re-install the High-Voltage shield (see the ‘ High-
Voltage Shield" reinstallation procedure in Section 6) or the
protective shield , depending on your instrument.
j. CHECK—Voltage levels of the remaining power
supplies listed in Table 5-2 are within their specified limits.
Table 5-2
POWER SUPPLY LIMITS AND RIPPLE
Power
Supply
Test
Point
Reading
(Volts)
P-P Ripple
(mV)
-8 .6 V TP500 -8 .5 6 to -8 .6 4 < 10
+ 5 V W985 4.75 to 5.25
< 10
+ 8.6 V W975 8.34 to 8.86
< 10
+ 3 0 V W965 28.5 to 31.5
< 5 0
+ 100 V
W966
95 to 105
<200
k. Connect the test oscilloscope, using a l x probe, to
the first test point indicated in Table 5-2 and connect the -
probe ground lead to TP501.
l
. CHECK— Ripple amplitude of the dc supply is within
the typical value given in Table 5-2.
m. Repeat parts k and I for each test point in Table 5-2.
n. Disconnect the test setup.
2. C h ec k H ig h -V o ltag e Supply
a. Set the POWER switch to OFF (button out).
b. Set the dc voltmeter to a range of at least —2500 V
dc and connect the volts lead to chassis ground. Remove
the crt base-socket cover and connect the common lead of
the dc voltmeter to pin 2 on the socket.
c. Set the POWER switch to ON (button in).
d. CHECK— High Voltage Supply dc level is —1900 V to
-2 1 0 0 V.
e. Set the POWER switch to OFF (button out).
f. Disconnect the voltmeter leads and re-install the crt
base-socket cover.
g. Set the POWER switch to ON (button in).
3. A d ju st C R T G rid B ias (R 860)
a. Set the A SEC/DIV switch to X-Y.
b. Rotate the AUTO INTENSITY control fully
counterclockwise.
c. Connect a 50
U
termination to the EXT Z AXIS INPUT
connector located on the rear panel.
d. ADJUST— Both the Grid Bias adjustment (R860) and
the AUTO FOCUS control for a visible dot. Then back off
the Grid Bias potentiometer until the dot just disappears.
e. Disconnect the test setup.
4. A d ju st A stigm atism a n d A u to Focus Tracking
(R 8 87 a n d R 875)
a. Set:
Channel 1 AC-GND-DC DC
A SEC/DIV 20
iiS
A TRIGGER MODE AUTO
REV NOV 1982
5-5