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Checks and Adjustments
5-26
1705A Spectrum Monitor
e. Turn the CENTER FREQUENCY control counterclockwise until the
frequency readout display is 1800 MHz.
f. ADJUST -- R38 (Offset) to position the 1800 MHz marker directly
under the caret.
g. Set the signal generator Frequency to 1000 MHz.
h. Turn the CENTER FREQUENCY control to display 1000 MHz.
i. ADJUST -- R37 (Offset Gain) to position the 1000 MHz marker directly
under the caret.
j. Repeat this step until the markers at 1800 and 1000 MHz are properly
positioned.
16. Adjust Intensified Zone Ran ge
a. Set the SPAN/DIV to FULL.
b. Set the signal generator Frequency to 1400 MHz, and Amplitude to --30
dBm.
c. Adjust the CENTER FREQUENCY control so the readout displays 1400
MHz.
d. ADJUST -- R61 to center the intensified zone on the 1400 MHz marker.
e. Set the leveled sine wave generator Frequency to 1000 MHz.
f. Turn the C ENTER FREQUENCY control counterclockwise to 1000
MHz.
g. ADJUST -- R 36 to center the intensified zone on the 900 MHz marker.
h. Repeat this step until the intensified zone is centered on appropriate
markers.
17. Adjust Vertical Gain
a. Set the 1705A SWEEP SPEED fully counterclockwise.
b. Set the signal generator Frequency to 1400 MHz, and Amplitude to
--30 dBm.
c. ADJUST -- R176 for a three-Division shift (±0.25 major Divisions)
when switching the input level between --30 and --60 dBm.
d. Set VERTICAL P OSITION to place the noise floor one major Division
up from the bottom graticule line.