Checks and Adjustments
5-24 1705A Spectrum Monitor
g. Set the signal generatorFrequency to 5.0 MHz, and the Amplitude to
+10 dBm.
h. Position the first marker at the extremeleft graticule.
i. ADJUST --R49, R56, R48, then adjust R57 to position one marker per
major Division over the 10 major graticuleDivisions, ±1 minor
Division. (All these adjustmentsaffect dc level of ramp start in 70 MHz
tuner.)
11. Adjust 10 kHz Filter
a. Remove the comb generator and reconnect t he cable from the signal
generatorto the 1705A 70 MHz INPUT.
b. Set the signal generatorFrequency to 70 MHz, and the Amplitude to --25
dBm.
c. On the 1705A set SPAN/DIVto 100 kHz, adjust CENTER FREQUEN-
CY to position the markeronto the screen, and set RESOLUTION to 10
kHz.
d. ADJUST --C52, C62, and C64 for a tall, symmetrical signal(¶6
Divisions).
e. Set RESOLUTION to 300 kHz, and turn SWEEP SPEED fully
counterclockwise.
f. ADJUS T -- R175 to match the signal amplitude of the highest point of
the 300 kHz filteredmarker with the tip of the 10 kHz filtered marker
while switching between10 kHz and 300 kHz RESOLUTION.
12. Adjust L--Band Linearity
a. Set INPUT to L--BANDand SPAN/DIV to 10 MHz. Adjust the
HORIZONTAL POSITION control to center the caret, and then s et
SPAN/DIVto FULL.
b. Connect the signal generatoroutput to the L--BAND INPUT.
c. Set the signal generatorFrequency to 900 MHz, and Amplitude to --30
dBm.
d. ADJUST --R35 to position the signal on the extreme left graticule.
e. Connect the signal generatoroutput to the L--BAND INPUT through the
comb generator.
f. Set the signal generatorFrequency to 100 MHz, and Amplitude to +10
dBm.