A direct conversion radio receiver is described which is characterized by many fewer spurious responses than the conventional superheterodyne, and lends itself to integration in monolithic form.The major design problem derives from the need for an accurate two-phase tunable local oscillator. A circuit is described which uses a servo-controlled phase shifting network, and maintains the two outputs within ±2° of quadrature from 66 to 95 MHz.Complete a.m. and s.s.b. receivers are described, and problems of a.g.c. discussed. The expected relative freedom from spurious responses was confirmed experimentally.