Sony Amplifier Mitsumi Radio Tuner

The Sony STR-K740P uses an advanced RDS tuner module manufactured by the Mitsumi Corporation. The FM signal feeds through a 75 Ω coaxial cable, and the tuner pack resolves the radio signal into left and right audio channels, which feeds the analogue sound processor chip (IC201). For the AM signal, you need to connect a loop antenna, however; in the pre-used markets, people often lose this antenna. One of these days, I must write a project article showing how one could be made at home.

• Antenna Type: Loop antenna
• Intermediate Frequency: 450 kHz
• Usable sensitivity: 50 dB/m (at 1,000 kHz or 999 kHz)
• S/N: 54 dB (at 50 mV/m)
• Harmonic distortion: 0.5 % (50 mV/m, 400 Hz)
• Selectivity: At 9 kHz: 35 dB, At 10 kHz: 40 dB

Mitsumi make some of the best tuners in the industry, and nearly all Japanese radio products found today will have a tuner made by them. The intermediate frequency (IF) for this tuner is 450 kHz.

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