Grid Bias (R2719); Astigmatism (R 2788); Astigmatism (R2788); Trace Rotation (Front Panel) - Tektronix 2246 1Y Service Manual

Table 5 - 2

Pow er Supply Voltage Limits

Nominal Test Point
(+ lead)
Supply
Voltage
+ 7.5 V J 1204-8
+ 130 V J1204-11
+ 59 V
J1204-10
+ 15 V J 1204-7
+ 5.0 V J 1204-1,2
-5.0 V J 1204-5
-7.5 V J 1204-9
-15 V J1204-6
2. Grid Bias (R 2 71 9 )
a. SET:
HORIZ MODE
CH 1 VOLTS/DIV
CH 1 COUPLING
BW LIMIT
A INTEN
B INTEN
READOUT (Intensity)
SCALE ILLUM
b. ADJUST-GRID BIAS (R2719) for a visible dot.
c. Position dot just off center screen with vertical or
horizontal POSITION controls.
d. Set FOCUS control for a well defined dot.
e. ADJUST-GRID BIAS (R2719) so that dot is no
longer visible.
3. Astigm atism (R 2788)
a. Set:
HORIZ MODE
A INTEN
READOUT (Intensity)
SEC/DIV
VAR SEC/DIV
CH 1 VOLTS/DIV
CH 1 COUPLING
b. Connect Leveled Sine-Wave Generator output to
the CH 1 input connector via a 50 C BNC coaxial ca-
REV JUN 1991
Adjustm ent Procedure —224 6 1Y and 2 2 4 6 M O D A Service
Limits
(0°C to 58°C)
Min Max
+ 7.42 to +7.57
+ 127.17 to +135.03
+ 55.74 to +59.18
+ 14.65 to +15.55
+ 5.05 to +5.25
-5.14 to -5.35
-7.48 to -7.78
-15.57 to -16.53
X-Y
5 V
GND
On
Fully CCW (off)
Fully CCW (off)
Fully CCW (off)
Fully CCW (off)
A
10 o 'clock
12 o'clock
5 p.s
Detent (fully CW)
10 mV
DC
ble and a 50 C BNC termination. Set for a 5-division
display at 50 kHz.
c. ADJUST-ASTIG (R2788) together with front-panel
FOCUS control for best overall resolution of the
sine-wave display.
DISCONNECT: Leveled Sine-Wave Generator.
4. Trace R otation (Front Panel)
a. Set CH 1 COUPLING to GND.
b. Position trace to center horizontal graticule line and
beginning of trace to first vertical graticule line.
c. ADJUST—TRACE ROTATION (front panel) to align
trace parallel with center horizontal graticule line.
5. G eo m etry (R 2784)
a. Set:
CH 1 VOLTS/DIV
CH 1 COUPLING
SEC/DIV
READOUT (intensity)
b. Connect Time Mark Generator to CH 1 via 50 n ca­
ble and 50 O termination. Display 10 jxs time marks.
c. Position base trace below bottom graticule line.
d. ADJUST—GEOM (R2784) for minimum bowing of
time marks across the full graticule area. Vertical
bowing of time mark across screen should be no
more than 0.1 division.
e. Disconnect Time Mark Generator.
6. Z -A x is R esponse (C 2 7 0 4 ) on instrum ents with
serial num bers of b elo w B 1 1 0 1 0 0 for the 2246
M O D A or b elow B 7 1 01 00 for the 2 24 6 1Y
a. Set:
READOUT (Intensity)
SEC/DIV
READOUT (Intensity)
b. Connect test oscilloscope with 10X probe to R2718
(either side).
c. A D JU S T-Z AXIS RESP
response possible of the signal displayed by the
test scope.
d. Disconnect test oscilloscope.
0.1 V
DC
50 p.s
Fully cow (off)
12 o'clock
5 iis
Fully CCW (off)
(C2704) for flattest
5 -5