Vertical; Initial Control Settings; Procedure; Vertical Output Gain (R703) And Readout Vertical Centering (R260) - Tektronix 2246 1Y Service Manual

Equipment Required (See Table 4-1):
Calibration Generator (PG506)
Leveled Sine-Wave Generator
50 H Coaxial Cable
a t th e b a c k o f th is m a n u a l fo r lo c a tio n s o f te s t p o in t s a n d a d ju s tm e n t s .

INITIAL CONTROL SETTINGS

Set:
Vertical MODE
INPUT COUPLING
VOLTS/DIV
Vertical POSITION
Controls
Horizontal MODE
A/B SELECT
SEC/DIV
Trigger LEVEL
HOLDOFF
SLOPE
Trigger MODE
Trigger SOURCE
Trigger COUPLING
MEASUREMENTS
MENU Displays
A INTEN
READOUT
FOCUS
SCALE ILLUM

PROCEDURE

1. Vertical Output Gain (R703) and Readout
Vertical Centering (R260)
a. Run ADJUST Vertical OUTPUT routine.
Select SERVICE MENU. Simultaneously press the top
and bottom m enu-item
Adjustment Procedure—2246 1Y and 2246 Mod A Service

VERTICAL

See ADJUSTMENT LOCATIONS
th e
CH 1 and CH 2
DC
0.1 V
12 o 'clock
A
A
0.1 ms
12 o 'clock
min (CCW)
- T
AUTO LEVEL
VERT
DC
OFF
OFF
10 o 'clock
12 o 'clock
for well defined
display
fully CCW
select buttons. Select
50 f l Termination
Precision Normalizer (20 pF)
s e c tio n
INTERNAL SETTINGS MENU.
button to underline selection, then press SELECT
button. Run ADJUST Vertical OUTPUT routine. Press
down-arrow button three times to underline selec­
tion, then press RUN button.
N O T E
F o r th is a d ju s tm e n t ,
M o d A m u s t b e p la c e d in th e " n o r m a l" o p e r ­
a tin g p o s it io n to a v o id
d u e to e ffe c ts o f th e e a r t h ' s m a g n e t ic fie ld .
b. ADJUST-VO GAIN
CENTERING (R260) alternately until dashed lines
produced by the diagnostics are aligned with
dotted lines on the graticule.
c. Press END button to end the ADJUST Vertical
OUTPUT routine. Then press QUIT button to quit
the Service Menu and return to the normal
oscilloscope display.

2. CH 1 Step Balance (R12)

a. Set:
Vertical MODE
CH 1 COUPLING
BW LIMIT
b. Position trace to center of screen.
c. ADJUST—R12 (CH 1 STEP BALANCE) so the
trace does not move vertically while switching
CH 1 VOLTS/DIV switch from 10 mV to 50 mV.
Press down-arrow
th e 2 2 4 6 1Y o r 2 2 4 6
in c o r r e c t a lig n m e n t
(R703) and RO VERT
CH 1 (CH 2 off)
GND
On
5-7