Abstract: Direct synthesis of a digital audio sample clock from a digital video sample clock is achieved by using a numerically controlled oscillator driven by the digital video sample clock. A phase accumulator increments a phase increment at the frequency of the digital video sample clock, the phase increment being a function of a desired frequency for the digital audio sample clock, the frequency of the digital video sample clock and the bit precision of the accumulator. The accumulated phase output from the accumulator is converted into a sine wave signal at the desired audio frequency from which the digital audio sample clock is derived.
Abstract: A cable television tuner including a tracking filter to receive the radio frequency signal of the cable television, microwave monolithic integrated circuit to changes the radio frequency signal into an intermediate frequency signal, an inband and outband matching network to match the impedance of the signal, a balance to unbalance transformer, a low pass filter to receive signal from the inband and outband matching network through the balance to unbalance transformer, a double tuned circuit device, a secondary mixer to changes the output signal of the double tuned circuit device, which is received from the low pass filter, into the desired intermediate frequency signal, a trap to remove the sound carrier frequency and image carrier frequency of the nearby channels from the signal received from the secondary wave mixer, ampli-filter to remove noises from the signal received from the trap, and an attenuator to attenuate the signal received from the ampli-filter so as to provide a satisfactory radio frequency ou
Abstract: The present invention relates to a T.V. tuner cassette insertable into a tape player. These tape players (or recorders) normally have magnetic pick-up heads, volume controls and other signal conditioning circuitry which collect and modify an audio signal prior to application of the audio signal to one or more speakers. The T.V. tuner cassette demodulates the audio components of the received T.V. signal and applies the demodulated audio component to the electronic circuitry in the tape player by an inductive or an electromagnetic link established with the magnetic pick-up head in the tape player and an inductive transmitter in the T.V. tuner cassette. The T.V. tuner cassette is powered from a power cable extending beyond or outboard of the tape player. The power cable, at its remote end, terminates in a cigarette lighter adapter plug. This plug fits into a standard cigarette lighter outlet. Mounted on the cigarette lighter adapter plug is a tuner control such that a user can select a T.V.