Vertical; Input Coupling Functional Check; Ch 1 And Ch 2 Volts/Div Trace Shift; Ch 1 And Ch 2 Volts/Div Trace S H Ift - Tektronix 2246 1Y Service Manual

Performance Check Procedure—2246 1Y and 2246 Mod A Service
Equipment Required (See Table 4-1)
Leveled sine-wave generator
Calibration generator
Function generator
50 f l BNC coaxial cable

1. Input COUPLING Functional Check

Set:
READOUT (Intensity)
A INTEN
Vertical MODE
CH 1 and CH 2
VOLTS/DIV
CH 1 and CH 2
Input COUPLING
A/B SELECT
Trigger MODE
Trigger SOURCE
Trigger CPLG
Trigger SLOPE
Trigger LEVEL
Trigger HOLDOFF
Horizontal POSITION
Horizontal MODE
SEC/DIV
FOCUS
Measurements
SCOPE BW
CH 2 INVERT
Set Vertical MODE to CH 1 (CH 2 o ff).
c. Connect calibration generator (PG 506) STD
AMPL output to the CH 1 input via a 50 f t BNC
coaxial cable.
d. Set calibration generator to STD AMPL and AM­
PLITUDE to 5 V.
4 -6

VERTICAL

e. Position the bottom of the signal to the center
horizontal graticule line.
f. Set CH 1 Input COUPLING to AC.
For a viewable
g. CHECK—display is roughly centered about the
readout
center horizontal graticule line.
For a viewable
trace
h. Move the test signal to the CH 2 input.
CH 1 and CH 2
i. Set Vertical MODE to CH 2 (CH 1 off).
1 V
j. Repeat the procedure for CH 2.
DC
k. Disconnect the test signal from the 2246 1Y or
A Trigger
2246 Mod A.
AUTO LEVEL
VERT
2.

CH 1 and CH 2 VOLTS/DIV Trace Shift

DC
_ ~ (positive)
j
a. Set:
12 o 'clock
Min
CH 1 and CH 2
12 o ' clock
Vertical MODE
A
CH 1 and CH 2
0.5 ms
VOLTS/DIV
For best
CH 1 and CH 2
defined display
Input COUPLING
All off (press
SCOPE BW
CLEAR
DISPLAY three
b. Set Vertical MODE to CH 1 (CH 2 off).
times)
Off
c. Position trace to center horizontal graticule line.
Off
d. Switch CH 1 VOLTS/DIV through all positions
from 2 mV to 5 V.
e. CHECK—trace shift does not exceed 0.2 division
f. Set Vertical MODE to CH 2 (CH 1 off).
g.
graticule line.
50 f l precision BNC coaxial cable
50 O termination
Adapter BNC-m ale-to-m iniature probe tip
Dual-input coupler
between steps.
Position CH 2 trace to the center horizontal
On
2 mV
GND
On