radio frequency

The IF signal frequency of FM radio is 10.7MHZ.

Intermediate frequency signal is a signal obtained by frequency conversion of high frequency signal. In order to make the amplifier work stably and reduce the interference, the general receiver should change the high frequency signal into the intermediate frequency signal.

FM radio is a radio that uses FM carrier to transmit radio signals. Because of the short wavelength, the transmitted signal is much better than that of AM-wavelength radio, but because it is short wave, the transmission distance is relatively short.

The TV image IF signal is 38MHZ, the audio IF signal is 6.5MHZ, the shortwave radio IF signal is 465KC, and the FM radio IF signal is 10.7MHZ.

Frequency range of audio signal and frequency range of intermediate frequency signal:

The audio range can generally be divided into four frequency bands:

1, low frequency band (30~ 150Hz).

2. Low frequency band (30~ 150Hz).

3. Low frequency (150~500Hz).

4. High frequency band (500~5000Hz).

5. High frequency band (5000 ~ 20000 Hz).

How to generate the second audio intermediate frequency signal: The intermediate frequency signal (including image and audio) from the intermediate frequency circuit is sent to the intermediate frequency demodulator, where it beats the audio intermediate frequency (3 1.5MHz) generated by the local oscillator to generate the audio intermediate frequency, which is generally 6.5MHz.