Abstract: This invention relates to tone generating systems for polyphonic electronic musical instruments. The system includes a plurality of programmable tone generators each of which is assigned to a different note to be sounded. For a preferred embodiment, one of the programmable tone generators is designated as a solo high tone generator, and is always utilized to produce the highest note to be sounded. Another generator may be designated as the solo low generator, and will always be utilized to generate the lowest note to be sounded. Additional solo note generators may be provided if desired. Tone generators are interconnected in a priority scheme with one generator at a time being designated as the next generator to be assigned a note to be sounded, and the designation being advanced in a predetermined manner as notes are assigned successively to the generators.

Abstract: A time-shared electronic musical instrument is provided with programmable wave-form generating and tone coloring circuits in order to maintain the musical characteristics regardless of pitch. The circuits comprise programmable keyers and wave-shapers, programmable envelope generators, programmable filters, and a programmable voicing selection circuit, in all of which certain characteristics of the output signal are tailored to the frequency of the musical tone.

Abstract: A reversible bracket assembly for use with an electronic apparatus bearing housing or the like includes an elongate plate having opposed sides each suitably fastenable to the side panels of the housing. A mounting flange extends transversely of and integrally from one end of the plate and a handle member extends integrally from the other end of the plate. The plate is fastenable to the housing with one of its sides in abutment with the housing side panels for facilitating portable transportation and use of the housing by means of the handle members and with its other side in abutment with the housing side panels for facilitating mounting of the housing within a standard equipment rack through the agency of the mounting flange.

Abstract: In an electronic musical instrument of the type in which pitch selection is achieved by pulse position modulation, and a rhythm accompaniment is played automatically under the direction of a read-only memory, a shift register is used to create pulse position modulation instructions for harmonic footages of the fundamental note, and selected combinations of these footages are rhythm-modulated and rhythm-counter-modulated under the control of logic gates which are responsive to various manually operated stop tabs.

Abstract: A distortion sound effects circuit producing an output signal corresponding to an input signal but containing one of four selected types of distortion. A compressor which includes a voltage-controlled amplifier first compresses the audio input signal within preselected limits, and the distortion operations are performed on the compressed audio signal to advantageously render the subsequent distortion operations insensitive to gross amplitude fluctuations of the input signal. The compressor includes means for full-wave rectifying the compressed audio signal. The full-wave rectified signal is provided as a distorted output signal containing hard-even distortion of the type commonly achieved by severely, asymmetrically clipping a signal. A distortion circuit includes single voltage controlled square-low amplifier to which the compressed audio signal is applied performs the other three types of distortion.

Abstract: A programmable dynamic filter for use with a time-shared electronic organ or the like includes a filter circuit responsive to a logical state of a control signal for tracking notes generated by the instrument. Means are provided for programming the filter independently of generated notes by selectively adjusting the pulse width of the control signal to achieve desired musical effects.

Abstract: A switch mechanism designed to overcome the problem of electrical noise employs a compound movable contact assembly, including a coil spring member and a smooth-surfaced wire contact member mounted thereon. The flexing of the coil spring provides an advantageous rolling, wiping motion for the wire contact member, without the noise-producing electrical discontinuities associated with earlier mechanisms in which the coil spring itself made direct electrical contact.

Abstract: A television window tuning system has duty cycle adjustment means for selectively varying the duty cycle of the tuner associated local oscillator signal. Increasing the duty cycle of the local oscillator signal effectively shifts the tuning window in frequency space in one direction while decreasing the duty cycle shifts the window in the opposite direction. In one embodiment of the invention, the duty cycle adjustment means is set for producing a 0% duty cycle oscillator signal for deriving a tuning window particularly adaptable for use with conventional AFC systems.

Abstract: An electronic television tuning system includes a channel number selection integrated circuit chip interfaced with a channel computer integrated circuit chip by a plurality of data lines. The channel number selection chip, in response to the partial or complete entry of a channel number by the viewer, develops multiplexed digital codes on the data lines representing the channel number entry and, in certain circumstances, a predefined blanking code. A display apparatus, coupled to the data lines, provides an observable indication of the channel number entry, portions of the display being suitably blanked in response to the blanking code. Tuning information and raster blanking signals are developed by the channel computer chip directly from the information supplied on the data lines.

Abstract: A deflection yoke for a television picture tube having coplanar in-line electron guns includes vertical and horizontal coil windings selected for providing self-convergence and north/south pin cushion correction. The desired characteristics are achieved by winding the vertical coil for converging the electron beams along the vertical axis of the picture tube viewing screen and by winding the horizontal coil in a saddle configuration wherein an aperture devoid of wire turns is provided in the front end of the horizontal coil facilitating the achievement of a high third harmonic content winding distribution simultaneously with a comparatively high fifth harmonic content winding distribution.

Abstract: An automatic rhythm generator of an electrical musical instrument including a rhythm pattern generator for rhythmically selecting for actuation different ones of a plurality of instrumentation circuits to be sounded and a strobe pulse generating circuit for establishing the appropriate pulse width of a drive pulse needed by each instrumentation circuit for proper actuation thereof. The rhythm pattern generator circuit selectively enables a plurality of drive gates respectively associated with the plurality of instrumentation circuits during selected ones of a succession of periodic rhythm cycles in accordance with a predetermined rhythm pattern. The strobe circuit is synchronized with the rhythm pattern generator and generates during each rhythm cycle a plurality of strobe pulses on a corresponding plurality of outputs respectively associated with the plurality of instrumentation circuits. Each of the strobe pulses has a width preselected for the instrumentation circuit with which it is associated.

Abstract: An encoder providing on a single terminal of a circuit package a composite serial data stream containing both stored data bits of a multistage binary memory and a clock signal needed for decoding the data. A parallel to serial converter serially shifts the stored binary data bits to an output thereof in response to clock pulses of an internal clock, and a logic circuit responsive to both the internal clock and the serial binary data from the converter generates first, second and third signals of amplitudes discernibly different from one another respectively in response to 1-state data bits, 0-state data bits and the termination of clock pulses. Two fixed inputs to the converter respectively provide a 1-state start bit at the beginning of the set of data bits and a 0-state stop bit at the end of the set of data bits for purposes of decoding. An amplitude discriminating decoder uses the periodic third signals and the start and stop bits to decode the serial data.

Abstract: In an audio amplifier for amplifying signals from an electric guitar or the like having a conventional tone control circuit for selectively emphasizing input signals in the bass, middle and treble frequency ranges of the instrument, a multifilter circuit for emphasizing input signals with frequencies in selected, relatively narrow, frequency bands in the upper portion of the frequency spectrum to minimize aural fatigue. The multifilter circuit comprises a plurality of parallel connected, two-pole, resonant filter sections with different, relatively narrow, resonant frequency bands separated from one another by an amount on the order of 1/4 octave and forms a signal path that supplements the signal path provided by the conventional tone control circuit. The signals produced on the output of the tone control circuit are mixed with the multifilter output signals.

Abstract: An automatic channel equalization system for use with a television receiver includes a control section for automatically operating a transversal equalizer according to the distortion exhibited by a reference signal transmitted through the channel. The television line including the transmitted reference signal is supplied to the control section through a time base expander enabling the implementation of a relatively fast sampling rate for achieving full bandwidth equalization of the channel with relatively slow-speed signal processing technology.

Abstract: A television tuner system includes a varactor diode as the frequency determining element and means lacking a fine tuning control for addressing the varactor. In the addressing means, a plurality of DC potentials, each defining the band edges of one of the 82 standard broadcast television channels, are selectively accessible for deriving a nominal tuning voltage defining a frequency near the center of a selected channel and a pair of control voltages defining a restricted range of frequencies about the channel center frequency. The nominal tuning voltage is initially supplied to the varactor for tuning to the channel center frequency and is subsequently decoupled therefrom wherein tuning is maintained within the restricted range of frequencies by confining the voltage supplied to the varactor between the pair of control voltages. Automatic frequency control means are used to tune the varactor to a received signal within the restricted range of frequencies.

Abstract: A ghost cancellation system includes a surface-wave device operable for developing a replica of the ghost component of a video signal, which replica is combined with the video signal to eliminate or cancel the ghost component. The surface-wave device comprises an input transducer responsive to a modulated video signal for launching uniform acoustic surface-waves along a path traversing a balanced pair of output transducers and impinging upon a reflector array. The reflector array includes means for initiating non-uniform surface-wave reflections suitable for causing the output transducers to develop an output electrical signal comprising the ghost replica.

Abstract: A low-pass filter useful in association with a phase locked loop for controlling the frequency of a voltage controlled oscillator on the basis of an error signal resulting from a comparison between a reference signal and the oscillator's output. The low-pass filter comprises means responsive to the error signal for developing an output current for charging or discharging a capacitive network according to the frequency and phase deviations represented by the error signal. For large frequency and phase deviations extended charging or discharging currents provide high acquisition speeds whereas, as the frequency and phase deviation represented by the error signal decreases, drastically reduced charging or discharging currents result thereby effectively reducing the bandwidth of the filter for facilitating reference signal sideband supression as frequency "lock-on" is approached and when phase lock is achieved.

Abstract: An electromagnetic deflection yoke includes saddle wound horizontal deflection coils mounted to a liner. The vertical coils are toroidally wound on a smooth, magnetically permeable core having the form of a segmented frusto-conic section and are in contact with the opposite side of the liner. Each vertical coil comprises a repeatable multilayer precision stack of wire turns with only the wire turns providing the support for maintaining the multilayer precision stack. The core has positioning notches which mate with locating tabs on the liner and provide for an accurate positioning of the vertical deflection coils with respect to the horizontal deflection coils.