c. Reset SCAN TIME PER DIVISION to 5 MILLISECONDS and adjust TRACE ALIGN so that the horizontal base line
of the CRT trace is exactly parallel to the horizontal graticule lines.
4-16. IF Section Adjustments
a. Adjust HORIZONTAL POSITION to center trace on CRT. Turn LOG REF LEVEL fully CCW. Then adjust
VERTICAL POSITION so that the trace lies on or as close as possible to the center horizontal graticule line.
Adjust HORIZONTAL POSITION to center the trace. Then adjust HORIZONTAL GAIN until trace is exactly 10
b. Adjust VERTICAL POSITION so that the horizontal base line of the CRT trace is exactly on the bottom 'horizontal
graticule line of the CRT. Set LOG REF LEVEL to 0 dBm.
c. Set SCAN WIDTH to 0-100 MHz. The display on the CRT now should be very similar to that shown in Figure 4-1.
(The amplitudes of the signals may vary from those pictured.) d. Note the inverted marker below the bottom
graticule line. This marker indicates the display center frequency of the ZERO and SCAN WIDTH PER DIVISION
tuning modes. Adjust the FREQUENCY control to place this marker exactly under the signal two divisions from
the left of center.
e. This signal is the 30 MHz calibrator signal. Tune the marker carefully to null the signal.
The other signals on the display are the 'zero frequency' First LO feed-through and the 60 MHz
and 90 MHz harmonics of the calibrator signal.
f. Set SCAN WIDTH PER DIVISION to .05 MHz and BANDWIDTH to 10 kHz.
g. Switch the red SCAN WIDTH control to PER DIVISION. The BANDWIDTH, SCAN WIDTH PER DIVISION, and
center frequency are now those selected in steps e and f. (The marker makes it easy to select any signal in 0100
MHz scan and to expand the display about that signal.)
h. Adjust FREQUENCY tuning to center 30 MHz calibrator signal, if necessary. Then reduce SCAN WIDTH PER
DIVISION to 10 kHz. Use FINE TUNE to center the signal on the display. (The First LO of the analyzer is
automatically phase-locked to a crystal oscillator reference for the blue color-coded SCAN WIDTH positions (20
kHz or less), since the TUNING STABILIZER is turned on. Therefore, the FREQUENCY control, which tunes the
First LO, should not be used to tune the analyzer; the frequency would tune in 100 kHz steps.)
i. Set LOG REF LEVEL to 30 dBm.
j. Adjust VERTICAL GAIN so that signal amplitude is exactly on the LOG REF (top) graticule line of the CRT.
k. Set LOG/LINEAR switch to LINEAR. Set LINEAR SENSITIVITY to 1 mV/div (1 mV x 1). Since. the 30 dBm
calibrator output is 7.1 mV (across 50 ohms), the CRT deflection should be 7.1 divisions.
I. Adjust AMPL CAL on 8553B for a 7.1 division CRT deflection, if necessary.
m. Repeat steps i through I until no further adjustment is necessary.