Superheterodyne receiver.

摘要

A superheterodyne receiver comprising a variable frequency oscillator of PLL (phase-locked loop) (30) type for implementing a first local oscillator and a variable frequency oscillator (41) for implementing a second local oscillator. At least the frequency of a first locally generated signal is varied at reception to vary a received frequency, the frequency of the first locally generated signal is set at frequency calibration to a level equal to the frequency of a first intermediate-frequency signal, the second intermediate-frequency signal is frequency-converted by a BFO signal to a signal having a frequency of voice band, and the frequency of a second locally generated signal is calibrated to set the frequency of the frequency-converted signal to a specified level. <IMAGE>