TB 9-6625-1914-35
(6) SCAN MODE switch to INT.
(7) SCAN TRIGGER control to AUTO.
(8) BASE LINE CLIPPER control fully ccw.
(9) WRITING SPEED-STD pushbutton pressed.
(10) PERSISTENCE switch to MIN.
(11) INTENSITY control to 12 o'clock.
h. Set LOG REF LEVEL switch fully ccw, then position trace to a convenient graticule
line, using VERTICAL POSITION control.
i. Set SCAN MODE switch to MAN (INT on model 8552A) and use MANUAL SCAN
control to bring dot to center of display screen. Adjust FOCUS and ASTIG controls for
smallest round dot possible.
j. Set SCAN MODE switch to INT and adjust TRACE ALIGN control to set trace
parallel to horizontal graticule lines.
k. Alternately adjust HORIZONTAL GAIN and HORIZONTAL POSITION controls so
that trace just fills horizontal graticule line.
l.
Position trace to bottom graticule line, using VERTICAL POSITION control.
NOTE
Ignore any slight misalignment of the trace.
m. Connect TRACKING GEN OUT connector to INPUT connector.
n. Set TRACKING GEN LEVEL control to CAL 100 mV and VIDEO FILTER
switch to 10 kHz.
o. Position trace to -70 dB graticule line at center of display screen, using LOG REF
LEVEL vernier.
NOTE
It may be necessary to adjust the AMPL CAL control to lower
trace.
p. Turn LOG REF LEVEL switch cw 7 steps (without moving vernier) while observing
the trace. Trace should move up in 10 dB steps. If trace does not move to top graticule line,
adjust VERTICAL GAIN control until trace is positioned at top graticule line.
q. Turn LOG REF LEVEL switch fully ccw and repeat o and p above until no further
adjustment is necessary.
r. Set LOG REF LEVEL switch to -20 dBV (vernier to zero) and adjust AMPL CAL
control to position trace at top graticule line at center of display screen.
s. Set LOG/LINEAR switch to LINEAR, LINEAR SENSITIVITY control to 20 mV
per division, and adjust AMPL CAL control if necessary to bring trace to fifth graticule line.
50
