Tektronix 2715 Locked 2nd LO

Adjustment Procedures
2715 Spectrum Analyzer Service Manual 5-33
f. Reset the VERT SCALE to 1 dB/div, and readjust t he capacitors for
maximum amplitude.
g. Disconnect the signal generatorfrom J180 and reconnect P180.
Use this procedure to adjust C204 and R535 on the 2nd LO board.
HTest equipmentrequired:
Multimeter (DMM)
1. Recall factory default power up settings by pressing UTIL 1 1.
2. Select the following settings on the SpectrumAnalyzer:
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 TP300 (Figure 5-- 4 on page5 --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 motherboard and is
adjusted using a nonmetallic tool. Move the loop up and down to vary thevoltage.
7. Check that a signal is present on screen(oscillator locked).
8. Cycle the POWER switch and return to the CAL MODE (pressUTIL 5 8).
9. Check that the 2nd LO is still locked (+8.6V is present at TP300).
10. Adjust R535 for a downward slope to the noise aboutthe on screen signal
(phase noise).
NOTE. When R535 is full counterclockwise,lock cannot be achieved.
Locked 2nd LO
Adjustment