Abstract: Apparatus for decoding a serial data stream having remote control informations. Detector means for detecting a serial data stream containing said remote control data are provided to supply a microprocessor with serial data. The microprocessor employs the programming steps of sampling the data at a rate in excess of two times the data rate. The number of consecutive samples of zero bits between samples of a one bit are as counted. A register is loaded with a one bit every time a one is sampled, and loaded with a zero bit when the number of consecutive zeros exceed a predetermined number.

Abstract: The method and apparatus for providing an AM stereo receiver suitable for receiving an AM/PM modulated RF carrier frequency, the receiver uses a standard AM detector to receive said AM/PM modulated intermediate frequency and to provide an 1+r signal. The stereo detector system further provides an 1-r signal and comprises means (104) for receiving and limiting the amplitude of the AM/PM modulated signal to eliminate the amplitude modulation therefrom and for providing a signal having phase modulation only. The limited AM/PM signal from limiter (104) is then provided to an FM quadrature detector (106) for recovering any PM signal. The PM signal detected and provided by said FM quadrature detector (106) is then integrated by an integrator (124) to provide a true PM signal. The output of integrator (124) is provided to a squelch gate (128) and to a means for sampling and determining the presence of a 5 Hz signal.

Abstract: A circuit for processing an angle modulated signal having amplitude modulation signal components in stereophonic broadcasting systems. An inverse modulation of a signal to be detected is provided over a first signal amplitude range, and a constant signal level is provided over a remaining range for signals having a marginal amplitude level. The discontinuity in the control range avoids noise expansion for high negative amplitude modulator levels for the signal to be angle modulated.

Abstract: A loudspeaker system (10) having improved directional and frequency response characteristics for use in connection with a sound system having at least two speakers such as a stereo system which is provided. The loudspeaker system includes a driver (14) for low frequencies and/or a full range of frequencies. This driver includes an electroacoustic transducer unit and a sound radiating face having a dustcap (16) and a diaphragm (36). A dispersion control member (34) is positioned at a preselected location such that it overlays a preselected portion of the sound radiating face of the speaker to enhance its directional characteristics. In this connection, the dispersion control member (34) comprises a layer of acoustical, semi-transparent foam having a preselected cross-sectional outline which preferably terminates in one substantially straight edge (38).

Abstract: A receiver for demodulating a stereophonic broadcast signal. Envelope detection is provided for a preselected radio frequency broadcast signal. Angle demodulation of a difference signal contained in the broadcast signal is provided at the radio frequency level avoiding the use of superheterodyne techniques. Improved linearity is achieved over detection techniques which operate at an intermediate frequency level. Receiver protection from excessive negative modulation peaks is provided as well as subsequent audio signal processing.

Abstract: Apparatus is provided for coupling one of two signal sources to the antenna terminals of a television receiver. An antenna switch is provided which includes solid state switching elements which when receiving a biasing voltage connects one of two input ports to an output port for delivering a signal to a television receiver. In the unbiased state, the remaining input port is connected to the television receiver antenna terminals. High isolation is provided to prevent stray radiation from one signal source being received by a second signal source.

Abstract: A nonlinear edge peaking system (10) is provided which reduces the rise and fall times of input signal transitions and prevents the introduction of excessive preshoot and overshoot. The system (10) includes a first circuit (76) which delays the input signal. A second circuit (48) which is connected in parallel with the first circuit produces an output which is the approximation of the absolute value of the widened second derivative having a preselected offset bias. A third circuit (42) connected in parallel with the first and second circuit produces at its output a delayed first derivative of the input signal. The combination of the output of the second and third circuit is differentiated, amplified, inverted and added to the delayed input signal producing a peaked or enhanced signal with reduced rise and fall times.

Abstract: Apparatus is described for transmitting and receiving stereophonic broadcasts in the low frequency commercial AM broadcast band. A transmitter is described which modulates the phase and amplitude of a broadcast signal with separate information signals. A pilot tone may also be included to identify the transmission as stereophonic. Receiving means for detecting the PM and AM components to derive separate signals for stereophonic reception are included.