Abstract: A voltage limiter for a coaxial cable line that carries an RF signal and an AC powering voltage signal is provided, including a signal input carrying a first AC voltage signal and an RF signal, a signal output arranged in series with the input and carrying the RF signal and a second AC voltage signal that is lower than the first AC voltage signal, and a voltage limiting mechanism arranged between the input and the output. The voltage limiting mechanism reduces the first AC voltage signal to the second AC voltage signal without substantially affecting the integrity of the RF signal.

Abstract: An apparatus for combining a plurality of CATV channel signals at the head end of a CATV distribution system including a first plurality of band-pass filters each having an input for receiving a separate predetermined channel signal and an output, the output of the band-pass filters being directly connected to one another, a second plurality of band-pass filters, each having an input for receiving a separate predetermined channel signal and an output, the output of the band-pass filters being directly connected to one another, and a combiner for combining the channel signals from the first plurality with the channel signals from the second plurality.

Abstract: An electronic signal filter is provided that includes a metal housing which has been adapted to be electrically grounded, and a circuit board positioned within the housing. The circuit board includes a first area and a second area, and has an electrically conductive trace formed on a portion of a top surface of the circuit board that provides electrical communication between the first and second areas of the circuit board. The filter further includes a metal shield connected to the housing, located between the first and second areas of the circuit board. The metal shield extends in a direction substantially perpendicular to the plane of the circuit board and has a slot formed therein for receiving the portion of the circuit board on which the electrically conductive trace is formed. The slot is dimensioned to provide a space between the metal shield and the conductive trace.

Abstract: A television transmission security system, including scrambling a television signal by suppressing at least one of the horizontal sync pulse and vertical blanking interval of the television signal; transmitting the scrambled television signal; generating, and separately transmitting along with the scrambled television signal, a pilot carrier that includes timing information corresponding to the horizontal sync pulse and/or vertical blanking interval; and descrambling the scrambled television signal including receiving the pilot carrier and periodically suppressing, in accordance with the timing information included in the pilot carrier, video information of the television signal to an extent whereby at least one of the horizontal sync pulse and vertical blanking interval becomes detectable by a television receiver, thereby initiating organized receipt and display of the television signal.

Abstract: A pre-emphasis network used in a television signal jamming encoder has a variable gain tuned amplifier first stage and an attenuable notch filter and variable gain broadband amplifier second stage. The notch filter is tuned to a center frequency above the television signal intermediate frequency's visual carrier frequency resulting in 15 dB of increased pre-emphasis and a time delay which compensates for a time delay imparted by a decoding network upon decoding of a signal jammed by this encoder.

Abstract: A method and apparatus for securing a television transmission signal from unauthorized reception is disclosed that employs a sideband interdiction technique. A portion of the signal's sideband content is enhanced such that the signal is rendered useless for reception. The signal is decoded by passing the signal through a passive all-pass delay-equalizer network at the site of the receiver.

Abstract: An in-band television signal scrambling method and apparatus are disclosed which employ a scrambler which receives and scrambles a television signal by suppressing the amplitude of the horizontal synchronizing signals contained therein to a point below the "black" level and which generates whiter-than-white timing pulses in the scrambled television signal for use by a descrambler in reconstructing the suppressed amplitude horizontal synchronizing signals, and one or more descramblers for detecting the whiter-than-white timing pulses in the scrambled television signal and generating therefrom switching signals for a switchable attenuator through which the scrambled television signal passes. The attenuator boosts the amplitude of the suppressed amplitude horizontal synchronizing signals relative to the remainder of the scrambled television signal, thereby restoring the scrambled television signal to an unscrambled condition.