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Adjustment Procedures
5-16
2715 Spectrum Analyzer Service Manual
Use this procedure to adjust C204 and R535 on the RF Mother board.
See Figure 5--4 for the location of adjustments on the 2nd LO board.
1. Select the following settings on the Spectrum Analyzer:
FREQUENCY 100 MHz
REFERENCE LEVEL --30 dBm
SPAN/DIV 5 MHz
RES BW 5 MHz
VIDEO FILTER On
VERT SCALE 10 dB /DIV
2. Enable the calibrator signal by pressing INPUT 9.
3. Set R535 to mid range. See Figure 5--4.
RF Mother Board
Converter
5MHz
Bandpass
Filter
Adjustments
R200 Level
R535 C204TP300
RF Attenuator
Figure 5- 4: Locked 2nd LO and 5 MHz Bandpass Filter Adjustments
4. Monitor TP 300 (Figure 5 --4) on the RF Mother board with the Multimeter.
5. Adjust C204 (Figure 5--4) until the oscillator locks. (The calibrator signal
should appear on-screen at this time.)
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 or down to vary the tune
voltage.
6. Note the voltage reading on the meter and adjust C204 for a tune voltage of
8.5to9.5V.
Locked 2
nd
LO Preset