Abstract: A method and apparatus is disclosed for automatically and repeatably measng the effectiveness of jamming applied against a communications link. The method is machine performed, free of the need of listener personnel, and the recording and scoring tasks required in conventional methods. Using a ratio of auto and cross-correlation functions, a number is produced (CCI Index) which is the desired measure of jamming effectiveness. The CCI Index is a standardized value which indicates jamming effectiveness in any type communications link regardless of equipment or type of modulation in use. The Index, rapidly obtainable, can be used to pinpoint which jamming technique might be most advantageously employed, and by precisely how many db it would be superior.

Abstract: A jammer transmitter having a comb spectrum generator which includes a pulse generator adapted to produce a pulse train at a frequency corresponding to the channel spacing of signals to be jammed, and a bandpass filter which has a passband including a bandwidth occupied by the signals to be jammed and which is responsive to the pulse train for providing within this bandwidth comb generator output signals at harmonics of the pulse train frequency, a power amplifier operative to amplify the comb generator output signals so as to produce jamming pulses and an aerial for radiating the jamming pulses, the width of the pulses of the pulse train being short enough to ensure that the harmonics of the pulse train frequency occur throughout the bandwidth.

Abstract: A siren alarm on an emergency vehicle or a like warning vehicle, for transmission forwardly over a limited range along the vehicle path, of a broadcast band carrier wave modulated with a siren signal with break-in possible for voice modulation of the carrier, with the carrier frequency rapidly and continuously repeatedly swept over the broadcast frequency band, both in the AM broadcast band and FM broadcast band, thereby to produce in other vehicles, having standard broadcast radio receivers in operation, a warning signal or voice communication; optionally with warning vehicle speed responsive control of the transmitter output power for establishing a transmission range proportional to the warning vehicle speed.

Abstract: There is disclosed a wired television system comprising a source of television signals supplying signals to a transmission network, subscriber stations connected to the network, means for preventing reception of transmitted signals by at least one subscriber station, and means for overriding the preventing means to enable that subscriber to receive the transmitted signals. The television signals are heterodyned with a scrambling signal to provide the transmitted signals, and the scrambling signal is transmitted over the network. At the subscriber station, the transmitted signals and the scrambling signal are heterodyned to recover the television signal.

Abstract: A digital noise generator, wherein pseudo-random rapidly changing analog input voltages to a voltage controlled oscillator are used to generate corresponding rapidly changing discrete frequency outputs, is disclosed. Means are provided to delay the oscillator output by an amount at least equal to the rise time between each frequency change. The delayed and non-delayed oscillator outputs are electrically coupled through a switch that operates at times and at a rate to eliminate the rise time between frequency changes and thus improve the frequency spectrum.

Abstract: In a communication system including communication transmitting means for modulating a carrier wave having a fixed frequency by a communication signal having communication content and for radiating the modulated signal wave, and receiving means for receiving the modulated signal radiated from the communication transmitting means to demodulate the communication signal, the communication system comprises a communication shielding area provided at a desired location on a boundary between communication areas for limiting the extent of the communication areas in which the modulated signal is transmitted, and shielding transmitting means for transmitting the shielding signal wave into said communication shielding area, the shielding signal wave being received by the receiving means tuned to the carrier wave frequency at a signal receiving level equal to or more than the receiving level of the modulated signal.

Abstract: Apparatus for generating signals to interfere with or jam signals detected as unfriendly in a given input frequency band comprises a spectrum analyzer circuit using surface acoustic wave (SAW) chirp filters to provide a transformation of input frequency signals to a series of time displaced signals in a linear frequency-to-time relationship. The analyzer circuit uses the SAW devices to perform multiply-convolve functions that separate the different frequency signals in time and the analyzer is repetitively triggered to perform a spectrum analysis. The time series signals are selectively applied to a frequency synthesizer having a time-to-frequency relationship that matches the analyzer characteristic so as to regenerate signals at the input frequencies. The synthesizer uses two matched chirp filters one activated by a fixed time signal and the other by the time series to generate swept frequencies that are mixed to provide the required frequency outputs.

Abstract: A waveform capable of jamming some or all of the channels of a multiple channel receiver is developed by a multi-tone jammer that uses a digital counter and a digital/analog converter to generate a ramp voltage for a voltage controlled oscillator (VCO). The output of the VCO is modulated by a pin diode attenuator. The attenuator is controlled by a pattern generator synchronized with the digital counter to blank the retrace and any portion of the sweep to provide a partial band tone jamming spectrum. The digital counter is driven by a MHz reference signal generator and the sweep repetition rate is greater than the circuit bandwidth.

Abstract: A communications management system includes a central processor (10) which is connected via an order wire subsystem (12) to various remote terminals (14, 16, 18). The central processor (10) maintains tables (42, 44) which relate remote terminals (14, 16, 18) to communication operating frequencies and assign jammers to selected operating frequencies. Further tables are maintained to list adversary frequencies (40), remote terminal locations (46) and remote terminal channel monitor assignments (48). Processor (10) develops the communications assignment table based on a preselected set of operating channels minus the channels being jammed or used by adversary parties. The channel assignments are changed on a recurring basis to reduce the probability of intercept and jamming. An operator console (24) is provided for displaying the data in the tables and for entering commands to update the tables.

Abstract: A simulated interference system is provided wherein an interference signal of an interference source is simulated by a narrow band coded control signal that is transmitted from a control transmitter to a target receiver that is engaged in normal communications. The control signal is received by the target receiver and is applied to an interference injector that is coupled to the antenna of the receiver. The interference injector decodes the control signal and couples a corresponding interference signal to the antenna of the receiver. The interference signal of the interference injector operates to disrupt the normal communications signals that are received by the target receiver.

Abstract: Apparatus for use with a television receiver for selectively inhibiting reception of television broadcast signals. The apparatus includes a number of signal generating circuits, each respectively set to generate an electrical signal substantially equal to the carrier frequency of a corresponding television broadcast signal, and timer capable of being preset to activate and deactivate selected oscillators on a timed basis. The signal generating circuits are coupled to the antenna input leads of the television receiver so that when activated the electrical signals produced thereby cause sufficient interference with the corresponding incoming television broadcast signal to effectively block reception.

Abstract: A method and system for disrupting discrete keyed continuous wave radio communications wherein the discrete keyed continuous wave communications signal conveys intelligence by virtue of the duration and spacing of a coded series of characters by insertion of additional character representing signals within the spaces between the characters of the original signal, thereby changing the coded series and thus depriving the intended recipient of the original intelligence.

Abstract: A digital memory system adapted to store a sequence of one bit quantized samples of an input signal having a frequency within a predetermined band of frequencies and to produce a replica of such input signal from such stored one bit samples. A control signal is produced indicative of the particular portion of the band of frequencies which includes the frequency of the input signal. A plurality of filters is provided, each one tuned to a different portion of the band. In response to the control signal the sequence of bits read from memory passes through the filter which is tuned to the portion of the band which includes the frequency of the input signal. With such arrangement many unwanted harmonics produced because of the one bit quantization of the input signal are removed.

Abstract: A frequency memory system having a smart noise component is receptive of an RF burst signal of a given frequency and of relatively short duration for determining the frequency and storing a signal of amplitude indicative of the given frequency and for producing by means of a voltage controlled oscillator (VCO) a signal at the given frequency of relatively long duration. The stored signal and a signal for amplitude corresponding to the actual frequency produced by VCO are utilized to produce an error signal to correct any error in the frequency of the signal produced by the VCO relative to the given frequency. Since the VCO is not capable of immediately accurately tracking the input frequency, a smart noise generator produces a signal of random amplitude which is added to the error signal to cause the VCO to produce at least a frequency component of its output signal which is equal to that of the input RF burst signal.

Abstract: A system for use in combination with (for electrical attachment to) electronic gear having an audio amplifier and which includes alarm means for generating a theft signal which is broadcast through a transmitter or audio system thereof and internal coded disable means for disabling the alarm upon insertion into the system of a predetermined coincidence signal that is substantially unique for each individual unit protected.

Abstract: 1.

Abstract: To alert users of Citizen-Band (CB) radios of an emergency situation, a CB transceiver has a tone generator associated therewith generating an emergency signal, for example a high pitched tone. Upon operation of an emergency switch, the transceiver is placed in the "transmit" mode, and the channels thereof are selectively stepped through for transmission, each one of the channels being modulated by the emergency high pitched tone signal generated in the emergency tone generator; the transceiver, finally, reaches a predetermined channel, for example channel 9, reserved for emergency communication and is thereupon switched to receiving mode. The emergency switch can be incorporated as part of an impact switch in a motor vehicle, thereby sending out the emergency signal, automatically, upon collision, and alerting other users of CB equipment that an emergency exists, regardless of the channels on which the other users may be operating.

Abstract: 1.