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Adjustment Procedures
2715 Spectrum Analyzer Service Manual
5-33
f. Reset the VERT SCALE to 1 dB/div, and readjust the capacitors for
maximum amplitude.
g. Disconnect the signal generator from J180 and reconnect P180.
Use this procedure to adjust C204 and R535 on the 2nd LO board.
H Test equipment required:
Multimeter (DMM)
1. Recall factory default power up settings by pressing UTIL 1 1.
2. Select the following settings on the Spectrum Analyzer:
FREQUENCY 100 MHz
REF LEVEL --30 dBm
SPAN/DIV 5 kHz
RES BW 300 Hz
3. Enable the calibrator signal by pressing INPUT 9.
4. Set R535 (Figure 5--4 on page 5--16) to midrange.
5. Monitor TP 300 (Figure 5 --4 on page 5--16) on the RF Mother board with the
Multimeter.
6. Adjust C204 (Figure 5--4 on page 5--16) for an indication of +8.6 V on the
Multimeter.
NOTE. C204 is a loop of wire on later versions of the RF mother board and is
adjusted using a nonmetallic tool. Move the loop up and down to vary the voltage.
7. Check that a signal is present on screen (oscillator locked).
8. Cycle the POWER switch and return to the CAL MODE (press UTIL 5 8).
9. Check that the
2
nd
LO is still locked (+8.6V is present at TP300).
10. Adjust R535 for a downward slope to the noise about the on screen signal
(phase noise).
NOTE. When R535 is full counterclockwise, lock cannot be achieved.
Locked 2
nd
LO
Adjustment