Tektronix 7D11 DIGITAL DELAY Service Instructions Manual page 42

Calibration-70 11 Service
v'i. CHECK-Using Table 4·5 as a guide, check for a
stable display for each condition given in both the
+
and -
TRIGGER SLOPE switch positions. Reset the TRIGGER
LEVEL control as necessary for a stable display. Set the
time-base unit sweep rate for optimum viewing of the
display.
TABLE 4-5
7011 Generator
Sine-Wave
COUPLING
Frequency
Amplitude
AC
10
megahertz
150 millivolts
AC LF REJ
10 megahertz 150 millivolts
DC
10 megahertz
150
millivolts
DC
50
megahertz
500 millivolts
AC LF REJ
50 megahertz
500
millivolts
AC
I
..
50 megahertz 500 millivolts
--------------~------~----~----
k. Disconnect the medium-frequency signal generator.
Retain the connection between the 7011 and the time-base
unit for the next step.
V8.
Check 7D11 Trigger Level Control Range
a. Set the COUPLING switch to AC.
b. Set the amplifier unit for a calibrated deflection
factor of .5 volt/division and the time-base unit for a sweep
rate of 10 microseconds/division.
c. Connect the low-frequency signal generator to the
EXT TRIG IN connector and to the amplifier ,unit.
4-10
d. Set the signal generator for a seven-division display
3.5
volts, peak-to-peak at
50
kilohertz.
v'e. CHECK-Rotate the TRIGGER LEVEL control
throughout its range and check that the delay can be trig-
gered at any point on the positive-going slope of the wave-
form. Set the TRIGGER SLOPE switch to - and repeat
this check for the negative-going slope of the waveform
(TRIGGER LEVEL range, at least
+1.75
volts to
-1.75
volts).
f. Disconnect all test equipment. Retain the connection
between the
7011
and the time-base unit for the next step.
V9.
Check Line Source Trigger
a. Set the SOURCE switch to LINE.
b. Set the time-base unit for a sweep rate of five
milliseconds/division and the amplifier unit for a deflection
factor of five or ten volts/division.
c. Connect a lOX probe to the amplifier-unit input.
Connect the probe tip to a line-voltage source.
v'd. CHECK-Set the TRIGGER LEVEL control to
light the TR IG'D indicator and check for a stable display.
e. Disconnect the lOX probe. Remove all plug-in units
from the mainframe.
REV. B, OCT. 1974