Tv Field Trigger Sensitivity; Tv Line Trigger Sensitivity; Line Trigger Functional Check - Tektronix 2246 1Y Service Manual

8. TV Field Trigger Sensitivity

a. Set:
Vertical MODE
CH 2 VOLTS/DIV
SEC/DIV
Trigger SLOPE
Trigger MODE
Trigger LEVEL
b. Connect TV signal generator negative-going
sync pulse output to the CH 1 input via a 50-0.
BNC cable.
c. Set CH 2 VAR VOLTS/DIV control for a 0.5 di­
vision composite sync signal.
d. CHECK—that a stable display is obtained.
e. Set:
CH 2 INVERT
Trigger SLOPE
f. CHECK—that a stable display is obtained.

9. TV Line Trigger Sensitivity

a. Set:
SEC/DIV
Trigger MODE
Trigger HOLDOFF
b. CHECK—that a stable display is obtained.
Performance Check Procedure—2246 1Y and 2246 Mod A Service
c.
CH 2 (CH 1 off)
2 V
d.
0.2 ms
~\_ (negative)
e.
TV FIELD
12 o ' clock
f.

10. Line Trigger Functional Check

a.
On
- T (positive)
b.
c.
20 p.s
TV LINE
For a single
d.
triggered
display
e.
Set:
CH 2 INVERT
Trigger SLOPE
CHECK—that a stable display is obtained.
Set CH 2 VAR VOLTS/DIV to Detent Position
(calibrated).
Disconnect the TV signal generator from the
2246 1Y or 2246 Mod A.
Set:
CH 2 VOLTS/DIV
CH 2 Input COUPLING
A SEC/DIV
Trigger MODE
Trigger SOURCE
Trigger CPLG
Connect a 10X probe to the CH 2 input
connector.
Attach the probe tip to a length of wire at least 4
in. long. Hold the wire near the instrument power
cord.
CHECK—that the display can be triggered in both
(positive) and (negative) slopes.
Disconnect the test setup.
Off
~\_ (negative)
0.1 V (without
a 10X probe
attached)
DC
5 ms
AUTO LEVEL
LINE
DC
4-17