Tektronix 2445A - Page 108

Performance Check-2445A/2455A Service
o. CHECK-Reading is either 59.5 ns to 60.5 ns or
69.5 ns to 70.5 ns.
6. Check Delta Time Accuracy.
a. Set the B TRIGGER MODE to MENU.
b. Turn either a control to underline RES.
c. Push the upper TRIGGER MODE button.
d. Turn either a to underline 10 ps.
e. Push the upper TRIGGER MODE button.
f. Set the A SEC/DIV to 1 µS (knob out).
g. Push NB MENU to access the B TRIGGER controls.
h. Push the lower TRIGGER MODE button to enter
TRIG
AFT DL y mode.
i. Set the time-mark generator to produce 1-µs time
markers.
j. Set the pulse generator to produce a positive 0.5-µs
pulse when externally triggered.
k. Push and release the at button until the Delta Time
readout appears.
I. Turn the a control to intensify the rising edge of the
second square
wave.
m. Turn the a REF OR DL Y POS control to intensify
the rising edge of the second square wave.
n. CHECK-Averaged at reading is between
+ 0.00005 µSand - 0.00005 µS.
o. Tum the a control to intensify the rising edge of the
eleventh square
wave.
4-30
p. CHECK-Averaged at reading is between
8.99990
µS and 9.00010 µS.
q. Set the A and B SEC/DIV to 100 µS (knob out).
r. Set the time-mark generator to produce 0.1-ms time
markers.
s. Set the pulse generator to produce a positive 50-µs
pulse when externally triggered.
t. Turn the a control to intensify the rising edge of the
eleventh square wave.
u. Turn the a REF OR DL Y POS control to intensify the
rising
edge of the second square wave.
v. CHECK-Reading is between + 899.996 µS and
+ 900.004 µS.
w. Press the upper TRIGGER MODE button to access
the
MENU.
x. If RES is not underlined, use the Delta controls to
underline
RES.
y. Press the upper TRIGGER MODE button.
z. Use the Delta controls to underline AUTO.
aa. Press the upper TRIGGER MODE button.
7. Verify Delay-By-Events.
a. Lock together the A SEC/DIV to 100 µs (knob in).
b. Set the A TRIGGER SLOPE to - (minus).
c. Push the at button until the at display disappears.
d. Push the NB MENU button.
e. Use either a control to underline DL Y /EVTS.