Abstract: A system for monitoring reverse paths of a bi-directional cable communication network such as a CATV network, to detect and analyze ingress signals entering a reverse path and ending at a network sub-headend or headend through a corresponding one of communication lines, comprises a plurality of radio frequency signal detectors connected thereto. The radio frequency signal detectors are provided with bandpass filter for receiving a radio frequency signal within the frequency band used, to generate corresponding output signals indicative of the strength of the received radio frequency signal. The output signal generated by the frequency signal detector which is coupled to the communication line corresponding to the ingress signal carrying path is indicative of the strength of the received ingress signal with received reverse signals.

Abstract: A method for detecting and quantifying impairments of a received communication signal of a QAM data communication system represented by a plurality of ideal values. The method includes storing a statistically significant number of a plurality of received points of the signal for each ideal value corresponding to a plurality of groups of said plurality of ideal values. The received points are defined by an in-phase and a quadrature components in a coordinate system in which a first axis is the in-phase axis and a second axis is a quadrature axis. The components have corresponding ideal components from their respective ideal value. Each group corresponds to respective impairments and is specific to the same.

Abstract: An antenna apparatus for detecting a leaked electromagnetic signal is provided. The apparatus includes a telescoping antenna and a casing, which has a portion of the antenna mounted in it. The antenna can move telescopically relative to the casing between an extended configuration, in which the antenna extends away from the casing, and a retracted configuration, in which the antenna is housed in the casing. A signal analyzer is located in the casing and is connected to the telescoping antenna. The antenna detects the electromagnetic signal, which is analyzed by the signal analyzer.

Abstract: A system and method for maintaining an uninterrupted data flow in a communications network includes a transmitter, which transmits the data flow from a data source and a receiver, which receives the data flow. A channel interconnects the transmitter and the receiver, and communicates the data flow between the transmitter and the receiver. A switch is located in the channel between the transmitter and the receiver. The switch is openable for a period of time, which is sufficient to permit analysis of signal impairment in the channel without interrupting the data flow.

Abstract: An antenna apparatus for detecting a leaked electromagnetic signal is provided. The apparatus includes a telescoping antenna and a casing, which has a portion of the antenna mounted in it. The antenna can move telescopically relative to the casing between an extended configuration, in which the antenna extends away from the casing, and a retracted configuration, in which the antenna is housed in the casing. A signal analyzer is located in the casing and is connected to the telescoping antenna. The antenna detects the electromagnetic signal, which is analyzed by the signal analyzer.

Abstract: A selectable band-pass filtering apparatus for use at the input of analysis instrumentation, such as a spectrum analyzer for testing a multi-channel communication system, comprises a high-pass filter section including a plurality of separate high-pass filters, each characterized by a respective high-pass cut-off frequency within a predetermined input frequency spectrum characterizing the communication system and a low-pass filter section including a plurality of separate low-pass filters each characterized by a corresponding low-pass cut-off frequency within the input frequency spectrum. The apparatus further comprises switching devices capable of connecting a selected high-pass filter In series with a selected low-pass filter in order to select passband having center frequency and bandwidth characteristics defined by corresponding high-pass cut-off frequency and low-pass cut-off frequency.

Abstract: A method for detecting and quantifying impairments of a received communication signal of a QAM data communication system represented by a plurality of ideal values. The method includes storing a statistically significant number of a plurality of received points of the signal for each ideal value corresponding to a plurality of groups of said plurality of ideal values. The received points are defined by an in-phase and a quadrature components in a coordinate system in which a first axis is the in-phase axis and a second axis is a quadrature axis. The components have corresponding ideal components from their respective ideal value. Each group corresponds to respective impairments and is specific to the same. The method also comprises analyzing the components of the points of respective group in relation with their respective ideal components to quantify the impairments of said signal and provide calculated values of the same.

Abstract: A radio transceiver having a receive mode and transmit mode is disclosed. The transceiver makes use of an application controller to control the operation of the transmitter and receiver portions of the transceiver. The application controller enables the control of a voltage source connected to the transmitter portion to vary the amplification gain of the transmitter section. The output of the transmitter and the input of the receiver are connected directly to the antenna circuit without the use of a duplexer. An oscillator circuit provides a transmission carrier during transmission and is used to convert signal frequency during reception of a signal. The controller can switch between the transmitting and receiving functions by activating and de-activating either one of the transmitter and receiver sections of the radio transceiver.

Abstract: A frequency generating means, generates an initial frequency of greater amplitude than the amplitude of a television signal carrier wave. The generated frequency is compared to a reference frequency which would be suitable for jamming one of the channels to be jammed. If the generated frequency is too high or too low, the frequency generating means generates a new frequency which is, respectively, either lower or higher than the initial frequency it generated. If the new generated frequency is still higher or lower than the reference frequency, the frequency generating means generates another new frequency, which is respectively, either lower or higher than the previously generated frequency, but by a lesser amount than the amount by which the previously generated frequency differed from the frequency generated before it. The generation of new frequencies continues until one of them is within a desired range of the reference frequency, at which time the generated frequency is stored in memory.

Abstract: Multiple latching relays are driven on their first side by all but one of the parallel outputs of a shift register. Each relay on the same shift register is driven on its second side by the remaining parallel output of the shift register. A clock signal is fed to all shift registers and causes each shift register to shift all of its information one cell on the selected edge of the clock signal. A latch signal or blanking signal is used to prevent the shift registers from outputting their information to the relays during shifting. A serial data message is inputted to the first shift register and then from the first shift register sequentially to all of the other shift registers. The information in the serial data message is such that after shifting of all shift registers is complete the appropriate signal will be on each side of each latching relay to cause it to either change or remain unchanged.

Abstract: A digital system for removing, from a television signal, the electrical noise generated by faulty isolators from power lines. A thin horizontal segment noise detector locates possible noisy pixels (picture elements), and an image horizontal line verifier prevents false alarms given by the noise detector. An image corrector is provided to remove detected noise. The real time algorithm described in the invention is designed to provide a robust detector pseudo independent of noise waveforms, a memory window of three video delay lines, and a low cost digital hardware system.

Abstract: A differentiation and distribution switching system for connecting selected ones of a plurality of subscriber lines for receiving a desired signal. The system comprises at least one differentiation circuit connected to an input signal, a removable support for the differentiation circuit, and a plurality of couplers connected to an output line of the differentiation circuit. A switch is connected to each coupler and an associated one of the subscriber lines, whereby to connect a signal on the output line to selected ones of the subscriber lines.