Abstract: A demodulator for demodulating a binary frequency-modulated signal includes a demodulator with a quadrature tank circuit and a duty cycle monitor circuit. The quadrature tank circuit has a voltage-controllable resonant frequency for compensating for shifts in the carrier frequency of the incoming signal and shifts in the tank circuit component values so as to allow the use of a high-Q tank circuit and thereby maximize use of the incoming signal energy. The quadrature tank circuit is a reactive circuit (with both inductive and capacitive elements) which includes a varactor diode having a voltage-controllable capacitance. The duty cycle monitor circuit measures the duty cycle of the demodulated binary output from the demodulator, and provides a control voltage to the quadrature tank circuit for adjusting its center frequency of operation.

Abstract: A bed plate (13) for a fluidized bed apparatus is made from a plate (23) from sheet metal and comprises openings (22) for fluidizing air or gas of the so-called "gill-type". In order to reduce or prevent fall-through of product, at least one of the edge portions (24,34) defining the opening (22) has been deformed so as to increase the extension thereof along the plane of the bed plate, and so as to thereby reduce or eliminate the orthographic projection on said plane of the opening (22). Such deformation may comprise compression and/or stretching. The edge portion or portions (24,34) are preferably deformed to such an extent that a partial overlap is obtained.