Tektronix SPG 1000, Instruction Manual

Page: 85 / 282

Performance Checks and Calibration
SPG 1000
6–25
n. Check that the multimeter reading is
+15 V. Typically this will be in the
range of +7 to +11 V.
o. Adjust the SPG 1000 fine timing until you
can toggle between .000us ADV and
0.000us DLY. Use the knob to go back
and forth across the jump threshold.
p. Check that the timing overlap is > 0.5 ns
and < 1.5 ns. If the overlap is < 0.5 ns
perform part q of this step. If the overlap
is > 1.5 ns, perform part r of this step.
q. Adjust R165 (ONLY if overlap is
< 0.5 ns) for an overlap of > 0.5 ns on the
oscilloscope, as the SPG 1000 is toggled
between .000us ADV and 0.000us DLY.
r. Adjust R164 (ONLY if overlap is >1.5ns)
for an overlap of <1.5 ns on the oscillo-
scope, as the SPG 1000 is toggled
between .000us ADV and 0.000us DLY.
s. Check that the multimeter reading is
+16 V. Typically this will be in the
range of +7 to +11 V.
t. Repeat parts o through s of this step for
the .000us ADV to .006us ADV transi-
tion.
u. Repeat parts o through t of this step until
the overlap and multimeter readings are
correct for both the .000us ADV and
0.000us DLY and the .000us ADV to
.006us ADV transitions.
v. Select an output standard that uses the
lowest frequency oscillator and repeat
parts o through t until the overlap and
multimeter readings are correct for both
the .000us ADV and 0.000us DLY and
the .000us ADV to .006us ADV transi-
tions.
w. Select an output standard that uses the
middle frequency oscillator and repeat
parts o through t until the overlap and
multimeter readings are correct for both
the .000us ADV and 0.000us DLY and
the .000us ADV to .006us ADV transi-
tions.
Output Amplifier Adjustments
7.
DC level adjustments
a. Connect the test equipment as shown in
Fig. 6–25.
b. At the front panel of the SPG 1000, select
Black (with the Test Signal select button.
and GBR output format (through the
Utilities menu), if necessary. Any output
standard may be used.
c. Adjust the oscilloscope to view the CH1
waveform with moderate vertical magnifi-
cation. Settings that are appropriate for a
Tek 2467B are listed in Table 6–18.
d. Set the oscilloscope CH1 Input Coupling
to GND. Use the vertical position control
to center the trace on the graticule.
e. Set the oscilloscope CH1 Input Coupling
to DC coupled. Adjust R8 for a G–chan-
nel blanking level of 0 V.
f. Move the coax from the G/Y output to the
B/P
B
output. Adjust R154 for a blanking
level of 0 V.