Abstract: Transmitters (1) of remote control systems are provided with surfaceacoustic-wave-resonators (42) and receivers (2) are provided with variable inductors (54,79) for aligning the receiver, to optimise the performance versus the costs. A receiver oscillating-filtering circuit (24) comprises a single transistor (74), capacitors (76,77) and a variable inductor (79) to create a kind of “filtering” oscillator. A receiver ripple rejecting circuit (25) improves the operation of the receiver oscillating-filtering circuit 24 and of a receiver amplifying circuit (23) comprising a cascade design of two transistors (66,67). A receiver filtering circuit (26) between the receiver oscillatingfiltering circuit (24) and a receiver amplifying-shaping circuit (27) improves the operation of the latter. A transmitter oscillating-amplifying circuit (12) comprises a single power transistor (46) operating as a Colpitts oscillator.

Abstract: A television tuner comprises a tunable bandpass filter (4) for selecting a desired input channel with an image canceling capacitor (C8) for rejecting the image frequency of the desired input channel. In order to avoid the necessity of different printed circuit boards for NTSC-type television tuners and for PAL-type television tuners, the image canceling capacitor (C8) is made of first (8) and second (10) traces of the printed circuit board while a third trace (13) is connected to the second trace (10) by a jumper (15) only in case of a PAL-type tuner.