Application of the loose-locked oscillator in a professional short-wave receiver

A description is given of the design and implementation of a loose¿locked oscillator (l.l.o.) tuning system with 1 Hz stepsize in a commercial communication receiver. A single tuning knob controls the tuning speed according to a non-linear joystick principle, not generallyused in this application. To estimate the established quality of the l.l.o. a comparison is made with a conventional synthesizer. The digital control facilities of the tuning system provide a conversion to convenient operation combined with good stability, which makes the receiver applicable to both fixed frequency and variable frequency communication links.