Abstract: A circuit for amplifying an input signal includes an output amplifier that develops an output signal including distortion at a first magnitude and phase displacement when a signal of a second magnitude is applied thereto and a further amplifier wherein the amplifiers have substantially identical gains and distortion characteristics and are operated at substantially the same input and output levels. The further amplifier is included in a circuit responsive to the input signal wherein the circuit provides an intermediate signal to the output amplifier. The intermediate signal includes a first signal portion comprising a scaled version of the input signal and a second signal portion comprising distortion at substantially the first magnitude and at a phase displacement substantially 180.degree. out of phase relative to the first phase displacement.

Abstract: A fiber optic communication system provides parallel paths to enable cancellation of even order harmonic distortion components. A pair of parallel optical fibers is provided. Each of the fibers is coupled to a corresponding transmitter at one end of the pair and to a corresponding receiver at the other end of the pair. The transmitters are modulated with an input signal applied to the transmitters at a 180.degree. phase differential. The 180.degree. phase shifted signals are combined at the receivers to recover the input signal while cancelling even order distortion products introduced by the transmitters. A method is provided for balancing the system upon installation.

Abstract: Switching apparatus for selectively applying either video game signals or conventional television program signals to a television receiver includes a pair of complementary filters to respectively pass and block the transmission of signals within a selected game-display channel. A switch may be selectively placed in either a game-playing mode or a program-receiving mode. In the latter mode the switch connects an input cable to the receiver. Correspondingly, when used for video games, the switch passes the incoming cable signal through one of the filters to a video game-playing adaptor and player which, in turn, are connected back to the receiver through the other of the filters.

Abstract: An improved system arrangement for distributing and permitting use of an ensemble of program controlled television games includes head end apparatus for impressing an array of game-regulating programs onto an electronic distribution system, e.g., by time division multiplexing into an assigned frequency band on a television program distributing CATV or MATV cable. At any of plural receiver locations connected to the distribution channel, a user desiring a game selects ("tunes") the game frequency band and loads a game program memory (RAM) with the program for the particular game desired. The composite apparatus then functions in the now per se conventional manner to actually implement the selected game in conjunction with a television receiver and player control(s).