9.3 MPX SECTION
1. Through 300 ohm dummy antenna, connect
FM signal generator to 300 ohm FM antenna
terminals.
2. Connect multiplex signal generator to extemal
modulation terminals of FM signal generator.
3. Connect oscilloscope
horizontal input to MPX
signal pilot output and vertical input via probe
to TP (No. 13) of circuit board.
sx-450
4. Set SX-450 dial indication to 98MHz and adjust
FM signal generator for center of scale indi-
cation on AM/FM meter.
5. With FM signal generator unmodulated, adjust
VR1 so that lissajous
pattern on oscilloscope
becomes
stationary as shown in Fig. 12.
6. With MPX signal generator
modulation lkHz,
L + R 67.5kHz deviation and pilot 7.5kHz
deviation, adjust T4 for minimum distortion.
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AC voltmeter Distortion
meter
FM signal
generator
Dummy load
Oscilloscope
MPX
signal
generator
Fig.12