Abstract: Manually tunable analog receivers with AFC have the drawback that the AFC exhibits hysteresis and that in the event of fading pulling to an adjacent station may occur, whereas receivers with PLL electronic tuning have the drawbacks that tuning is comparatively slow and also inaccurate because of the tuning in discrete steps by a microprocessor. The present receiver combines the advantages of both analog manual tuning and electronic tuning. It includes two cooperating frequency loops, one loop (L1) being an AFC loop and the other loop (L2) having a frequency counter (13) for measuring the frequency (f.sub.0) of a tuning oscillator (6) which is controlled by both loops. Cooperation between the loops is provided by a control circuit (16) responsive to control signals supplied by both loops: an in-lock signal (in-1) and an in-window signal (in-w). Preferably, when the desired tuning is achieved, the power to a tuning section (12) of the receiver, forming part of the frequency loop (L2), is interrupted.

Abstract: A receiver having an RF section, a mixer stage and a signal processing stage, the mixer stage receiving a mixing frequency from a frequency synthesis circuit which includes a phase-locked loop provided with a phase detection device having a current output, a loop filter including a .pi.-shaped RC network having an input shunt path and an output shunt path which are connected to respective ends of a series resistor incorporated in a series path, and to ground, and include first and second capacitances, respectively, and with a voltage-controlled oscillator, a reference frequency being applied to the phase detection device.