Time And Cursors Measurements; Cursor Accuracy; Delta Time Accuracy; Accuracy - Tektronix 2246 1Y Service Manual

TIME AND CURSORS MEASUREMENTS

Equipment Required (See Table 4-1)
Time mark generator
5 0 0 BNC coaxial cable
1.K-SEC-*! and k- 1/SEC-H Cursor Accuracy
a. Set:
READOUT (Intensity)
A INTEN
Vertical MODE
CH 1 VOLTS/DIV
CH 1 and CH 2
Input COUPLING
Horizontal MODE
A SEC/DIV
A/B SELECT
Trigger MODE
Trigger CPLG
Trigger SOURCE
Trigger SLOPE
Trigger HOLDOFF
CH 2 INVERT
SCOPE BW
FOCUS
b. Connect tim e-m ark generator (TG 501) output
via a 5 0 -0 BNC coaxial cable and a 5 0 -0 BNC
termination to the CH 1 input.
c. Set tim e-m ark generator for 1 ms time markers.
d. Position first time marker horizontally to the first
vertical graticule line (left-m ost edge of the
graticule).
e. Press TIME button to display the TIME menu.
f. Press k-SEC-H menu button to turn on time
cursors.
g. Position the reference cursor to the second time
marker and the delta cursor to the tenth time
marker.
Performance Check Procedure—2246 1Y and 2246 Mod A Service
h. CHECK—that
8.060 ms.
i. Press the TIME button to display the TIME menu.
For a viewable
readout j. Set k- 1/SEC-H on.
For a viewable
trace
k. CHECK—that the readout is 124 Hz 126 Hz.
CH 1
(all others off)
2.

Delta Time Accuracy

0.5 V
a. Set A TIME/DIV to 1 p.s.
DC
A
b. Set the tim e-m ark generator for 1-(is time
1 ms
marks.
A Trigger
AUTO LEVEL
c. Position the trace to the upper portion of the crt
DC
display and align the time markers horizontally
VERT
with the graticule.
- T (positive)
Min
d. Set:
Off
Off
Horizontal MODE
For best
B TIME/DIV
defined display
B TRIGGER MODE
k-SEC-H
e. Center the first intensified zone over the time
marker corresponding to the second graticule
line, and the second intensified zone over the
time marker corresponding to the tenth graticule
line.
f. Position the B sweep display to the lower portion
of the crt using the TRACE SEP control, and use
the -H control to align the delayed sweep so that
the selected time markers overlap each other
exactly.
g. CHECK—that the readout is between 7.910
and 8,090 |xs.
Calibration generator
50 0 BNC termination
the readout is
ALT
50 ns
RUNS AFTER
On
7.940 ms to
.
jj s
4-23