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 forthe location of adjustments on the 2nd LO board.
1. Select the following settings on the Spectrum Analyzer:
FREQUENCY 100 MHz
REFERENCE LEVEL --30 dB m
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 MotherBoard
Converter 5MHz
Bandpass
Filter
Adjustments
R200Level
R535 C204TP300
RFAttenuator
Figure 5- 4: Locked 2nd LO and 5 MHzBandpass Filter Adjustm ents
4. Monitor TP300 (Figure 5-- 4) on theR F Motherboard with the Multimeter.
5. Adjust C204 (Figure 5--4) until the oscillator locks. (The calibrator signal
should appear on-screenat this time.)
NOTE. C204 is a loop of wire on later versions of the RF motherboard and is
adjusted using a nonmetallic tool. Move the loop up or down to vary thetune
voltage.
6. Note the voltage reading on the meter and adjust C204 for a tune voltage of
8.5to9.5V.
Locked 2nd LO Preset