H03J3/28—Continuous tuning of more than one resonant circuit simultaneously, the tuning frequencies of the circuits having a substantially constant difference throughout the tuning range
Superheterodyne receiver having at least one downconversion stage empolying a single image reject filter stage and both low-side injection and high-side injection of a local oscillator signal
Dispositif et procede pour produire un signal filtre ayant une frequence donnee et emetteur hertzien emettant a une frequence etablie par un oscillateur reglable en frequence