S E N S Itiv Ity; Triggering; Hz Trigger Sensitivity - Tektronix 2246 1Y Service Manual

Performance Check Procedure—2246 IV and 2246 Mod A Service
Equipment Required (See Table 4-1)
Leveled sine-wave generator
50 O BNC coaxial cable
2X BNC attenuator
Dual-input coupler

1. 500 Hz Trigger Sensitivity

Set:
READOUT (Intensity)
A INTEN
Vertical MODE
CH 1 and CH 2 Input
COUPLING
CH 1 VOLTS/DIV
SCOPE BW
Horizontal MODE
A SEC/DIV
A/B SELECT
Trigger MODE
Trigger SOURCE
Trigger CPLG
Trigger SLOPE
Trigger HOLDOFF
FOCUS
Measurements
Horizontal POSITION
b. Connect function generator (FG 502) output to
the CH 1 input via a 5 0 -0 BNC coaxial cable,
and a 5 0 -0 BNC termination.
c. Set function generator (FG 502) output to pro­
duce a 7.0 division sine-wave display at 500 Hz.
d. Add a 10X and a 2X BNC attenuator before the
5 0 -0 BNC termination
display).
4-14

TRIGGERING

For a viewable
readout
For a viewable
trace
CH 1
DC
0.1 V
On
A
2 ms
A Trigger
AUTO LEVEL
VERT
AC
_ r (positive)
Min
For best
defined display
All off (press
CLEAR
DISPLAY three
times)
12 o 'clock
(for a 0.35 division
Function generator
10X BNC attenuator
50 O BNC termination
TV signal generator
NOTE
The Trigger LEVEL control may be used
to obtain a stable display.
e. CHECK—that the display is stably triggered with
DC, HF REJ, and AC Trigger CPLG; and that the
display will not trigger on NOISE REJ or LF REJ
Trigger CPLG.
f. Set:
Trigger CPLG
A/B SELECT
Trigger MODE
Trigger SOURCE
Trigger SLOPE
Horizontal MODE
B SEC/DIV
DELAY Time
B INTEN
NOTE
It may be necessary to adjust the Trigger
LEVEL control to obtain a display.
g. CHECK—that using the Trigger LEVEL control the
display can be stably triggered in DC, HF REJ,
and AC Trigger CPLG; and that the display can­
not be triggered in NOISE REJ or LF REJ Trigger
CPLG.
h. Disconnect the test setup from the CH 1 input.
DC
B Trigger
NORM
VERT
_v~ (positive)
B
0.5 ms
70.000
(minimum
delay time)
For viewable
display