f. Switch the band selector to A, adjust the GAIN con-
TABLE
5-3
trol if required for a satisfactory 1 MHz marker amplitude
and turn the RF CENTER FREQUENCY control to align the
tunable markers with the fixed markers.
g. Check the frequency of the Internal Reference oscillator
by aligning the 1st marker with the 1st graticule line and
noting the displacement of the 9th marker from the 9th
graticule line. (The INT REF FREQ control must be turned
to the initial on position to make this frequency check.)
There should be no noticeable difference in the postion of
the marker with the position noted in step e.
h. Set the DISPERSION RANGE to kHz/DIV and the DIS-
PERSION to 100 kHz/div.
i. Position a 1 MHz marker to the screen center with the
IF CENTER FREQ control.
Decrease the sweep rate as the dispersion is decreased
j. Adjust the INT REF FREQ-VARIABLE control through its
and increase resolution by uncoupling the RESOLUTION
range and note the frequency shift af the Internal Reference
control and turning it counterclockwise to optimize marker
oscillator. The display is the 200th harmonic of the 1 MHz
definition. Switch the VERTICAL DISPLAY to LOG and the
marker signal. The range of the VARIABLE control will also
VIDEO FILTER on, at these slower sweep rates and narrow
be related to the 200th harmonic, so the marker signal should
dispersion selections.
shift 2 to 2.6 divisions (1 kHz to less than 1.3 kHz).
g. Turn the VIDEO FILTER to OFF position and the VERTI-
k. Remove the cable between the 1 MHz MARKERS OUT
CAL DISPLAY selector to LIN.
connector and the RF INPUT connector. Remove the Time-
Mark Generator. Set the band selector to C.
15. Check Internal Reference Frequency
16. Check Phase Lock Balance Between Band
a. Requirement-Frequency is 1 MHz 0.1%, variable
A or B and Band C
frequency range is equal to or greater than 1 kHz, but not
a. Requirement-Band A or B, DC output level, with the
over 1.3 kHz, above the measured frequency when the con-
FINE RF CENTER FREQ control centered, should measure
trol is in the initial on position.
within 2 divisions of band C, DC output level.
b. Apply 10 ns and 1 s markers from the Time-Mark
b. With the band selector in position C, push the LOCK
Generator to the band B RF INPUT connector through a
CHECK button and position the sweep to the center of the
20 dB attenuator.
graticule with the FINE RF CENTER FREQ control.
c. Apply the 1 MHz MARKERS OUT signal to band A
c. Switch the band selector to band A or B and check
RF INPUT connector,
the position of the trace. Trace position must be within 2
divisions of the graticule center.
d. Set the DISPERSION to 1 MHz/div, the TIME/DIV to
5 ms and the band selector to B.
17. Check Dynamic Range of Vertical Display
e. Align the 1 s markers to the graticule lines with the
Modes
IF CENTER FREQ control. If necessary, adjust the DISPER-
a. Requirement-The dynamic range of the screen for the
SION-CAL to calibrate the display. Note the displacement
three display modes is as follows:
of the 9th time marker at the 9th graticule line.
5-7
