Abstract: A radio receiver simultaneously achieves maximum sensitivity and minimum susceptibility to intermodulation distortion by employing wideband and narrowband automatic gain control which further selects the automatic gain control response in dependence on the detection of intermodulation distortion. An AGC signal is modified to improve sensitivity in the event of a low narrowband signal level except when intermodulation distortion is detected above a predetermined distortion level.

Abstract: A frequency-shift keying (FSK) signal detector splits an FSK signal into two paths. In one path, a phase-altering circuit having a variable frequency characteristic between the two encoding frequencies of the FSK signal provides either a phase lead or a phase lag depending upon the instantaneous frequency of the FSK signal. The phase-altered signal is sampled in response to the signal in the second path to decode a digital signal.

Abstract: The radio receiver of the present invention detects the presence of adjacent channel interference in either the lower adjacent channel or the upper adjacent channel and shifts the received signals to remove the adjacent channel interference from the intermediate frequency passband, but only if the other adjacent channel is clear. A maximum amount of the desired signal is retained so that modulation distortion is low. Frequency limits for shifting of the desired signals prevent undesirable amounts of phase distortion from being introduced into the audio signal.

Abstract: A frequency modulation (FM) stereo broadcast receiver detects the onset of multipath interference and initiates corrective action to minimize the audible effects of multipath. Under an unacceptable multipath interference condition, a multipath detection signal disables the FM RF mixer thereby preventing any further energy in the multipath event from entering succeeding sections of the receiver. This action reduces noise generated by multipath interference and allows the output to return to normal in a shorter time. In another aspect of the invention, a phase-locked loop employed in a stereo decoder circuit is latched during the multipath disturbance in order to avoid rapid changes in the phase of the regenerated pilot employed in the stereo decoder.

Abstract: A variable bandpass filter for filtering RF antenna signals to improve selectivity and reduce intermodulation distortion in an FM radio receiver includes a series resonant circuit which is modified to avoid blocking of AM signals. A bypass inductor is connected in parallel with the series resonant capacitor. The bypass inductor has a self-resonant frequency located between the AM and FM bands so that series resonant performance is maintained at FM frequencies and the bypassing function is exhibited at AM frequencies.

Abstract: The reception of FM broadcast signals having a selected high sound quality is determined according to criteria including a low noise level and the absence of interference. The high quality information is employed to terminate a scan tuning operation or to activate an ultrasonic noise filter to improve listening quality of the FM audio output. The absence of noise and interference is determined by examining a particular frequency range from the FM field intensity line generated by an intermediate frequency circuit.

Abstract: The stereo separation provided by a radio receiver is controlled in dependence on the radio frequency environment at the receiver antenna. The blend curve for determining stereo separation in dependence on the field intensity of a received signal is dynamically shifted to maintain the average magnitude of a blend control signal at a predetermined magnitude if the field intensity is above a threshold. Otherwise the blend control signal follows a lower limit blend curve of predetermined shape.

Abstract: An FM broadcast receiver includes apparatus for measuring signal quality. Signal-to-noise ratio in the received signal is determined by isolating a noise component of the received audio signal, multiplying the isolated noise component by a gain determined by received field intensity, and comparing peak amplified noise against a reference. The derived signal-to-noise ratio can be employed to stop an automatic scan tuning operation or can be employed to provide a display of received signal-to-noise ratio.

Abstract: A composite core transformer has a high permeability segment and a low permeability segment such that a saturable portion of the core is used to control RF energy coupled from a receiving antenna to a radio receiver. Transformer input and output windings are wound on the low permeability segment of the composite core. A control winding is wound on the high permeability segment of the core and receives an automatic gain control signal from a radio receiver. The resulting radio receiver has high resistance to overload and an extended dynamic range of automatic gain control.

Abstract: The aircraft propulsive unit having on the one hand, a fixed central structure in the axis of which is housed a gas generator whose nozzle delivers a hot jet and, on the other hand, an upstream fan or blower concentric with the gas generator and rotating inside an annular channel defined by the fixed structure and by a peripheral cowling or fairing with double wall carried by the fixed structure, the blower providing the forced circulation of a cold flow in the channel for improving the performance of the power unit, the fairing being formed of two parts, the upstream one of which is fixed and surrounds the blower, whereas the downstream one is mobile and slides parallel to the axis x--x' of the generator, the propulsive power unit further having a system for reversing the thrust of the cold flow which is formed of pivoting doors having respectively external and internal walls which, in the retracted position of the doors, are aligned respectively with the external and internal walls of the fairing.

Abstract: A vertical dropshaft having internal helicoidal ramps for dissipating the energy of liquid passing through the dropshaft and for exhausting air entrained by the falling liquid up the center of the dropshaft.

Abstract: A flow-training structure for use in rivers and streams to minimize bank erosion, and to control bed degradation and aggradation. The structure consists of single vanes or arrays of vanes of a particular double-curved design. The vanes are installed in the river bed in designed arrays to produce changes in the local directions of the near-bed velocity, without changing the sediment-transport or flow-conveyance capacities of the channel.

Abstract: The invention provides a thrust inverser for a jet engine comprising doors 5-6 pivotably mounted at 14 on two beams diametrically opposite with respect to the gas discharge channel 2. The mechanism for operating the doors is entirely contained in the closed caisson formed by one of the beams 3, this mechanism comprising an actuating cylinder 15 driving a transmission piece 21 suspended from the beam 3, the transmission piece being coupled to two links 28 pivotably secured to the doors 5 and 6.

Abstract: The invention relates to thrust reversal devices for jet aircraft turboreactors and particularly for a turbo-fan type engine.The casing E surrounding the engine structure D comprises an intermediate section S3 formed by doors P4 pivoting about an axis 17-17' extending along a chord of passage CA so that the rear part of the door is short, which provides considerable clearance for the doors which may open up to 90.degree., as well as an action of flux F1 flowing in the passage promoting opening of the doors. A jack 21 coupled to each of the doors acts between the fixed structure of the casing and the internal part of the door.

Abstract: The engine is of the type having a central body surrounded by a casing defining therebetween a duct for the passage of the flux. The casing comprises a fixed upstream section extended downstream by means in which are housed jacks; a downstream section movable axially to which are fixed the rods of the jacks; and an intermediate section formed of swinging doors mounted between the beams and hinged thereto by lateral pivots, each door being coupled to the mobile downstream section by means of a hinged link so that the movement of the downstream section causes the doors to swing. This type of reverser is designed more especially for turbo-fan engines having a lateral nacelle configuration in which the whole of the flux flows in the annular duct between the central body and the casing.

Abstract: An electronic governor control for an automotive engine that prevents the speed of the engine from exceeding a predetermined limit. The electronic circuitry responds to ignition pulses and limits the throttle opening of the vehicle to maintain the predetermined speed limit. The electronic governor control also includes circuitry to prevent engine overshoot of the predetermined limit by monitoring the rate of acceleration and adjusting the predetermined limit to anticipate and initiate governor control prior to the engine reaching the predetermined speed limit. Circuitry is also included which allows the governor control to retain control of the engine until the accelerator control reduces the speed of the engine to a speed value below the predetermined limit.

Abstract: Fermentation process, e.g. for the production of an oxidation product such as vinegar, which comprises continuously cultivating a bacterial strain, preferably in a vessel of elongated shape, in a medium containing the substrate to be fermented in the presence of a hydrous oxide of a metal selected from the group consisting of titanium, vanadium, zirconium, iron and tin and a chelated polyhydroxy support. The bacterial strain used in the process is preferably chelated or complexed with the hydrous metal oxide and the polyhydroxy support.