Apparatus and method for interfering with radio communications

Claim 2

A radio communication interference system for destroying the intelligibility of a substantially continuous intelligence signal modulated upon a carrier signal, said system comprising: means responsive to said carrier signal for demodulating said carrier signal and for deriving said intelligence signal exclusively during one portion of a duty cycle which is independent of said intelligence signal, means responsive to said derived intelligence signal for continuously delaying said intelligence signal by different amounts of time to form a plurality of differently delayed by overlapping intelligence signals; means responsive to said plurality of delayed and overlapping signals for summing said last mentioned signals to form a scrambled intelligence signal; means for developing a further carrier signal which is of the same frequency as said carrier signal; and means responsive to said further carrier signal and said scrambled intelligence signal for modulating said further carrier signal with said scrambled intelligence signal and for transmitting the so modulated further carrier signal exclusively during the other portion of said duty cycle.

Claim 3

A radio interference system in accordance with claim 1 which said means for continuously delaying said intelligence signals comprises a means for temporarily storing said intelligence signal upon a record member.

Claim 4

A radio interference system in accordance with claim 1 in which said means for continuously delaying said intelligence signal comprises: a movable magnetic tape; a recording head disposed in recording relationship to said tape and having said intelligence signal applied thereto; a plurality of reproduce heads spaced along said tape in reproducing relationship to said tape and down stream from said recording head, each of said reproduce heads providing one of said delayed intelligence signals and means for moving said tape.

Claim 5

A radio interference system in accordance with claim 1 in which said means for receiving said carrier signal comprises a receiving antenna; a tunable receiver; a switch means, operable by a switching signal for connecting said antenna to said receiver; and lock means for providing said switching signal during the said one portion of the duty cycle.

Claim 6

A radio interference system in accordance with claim 4 in which said means for modulating said further carrier signal comprises: a modulator; a further switch means connecting said means for developing said further carrier signal to said modulator, said further switch means being operable by said switching signal and being constructed to assume its closed position when said switch means assumes its open position, and an open position when said switch means assumes its closed position; and transmit antenna means connected to said modulator.

Claim 7

A radio interference system in accordance with claim 1 in which the two portions of said duty cycle are of substantially the same duration.

Claim 8

A radio communication interference system for destroying the intelligibility of an intelligence signal modulated upon a carrier signal, said system comprising: receiver means responsive to said carrier signal and operative to demodulate said carrier signal to derive said intelligence signal; first switching means associated with said receiver means for controlling deriving said intelligence signal, said switching means being normally in the closed position for deriving said intelligence signal and being responsive to a switching signal to open the same and to thereby discontinue deriving said intelligence signal; signal delay means responsive to said derived intelligence signal and operative to delay the same by a plurality of different times to provide a plurality of delayed but overlapping intelligence signals, summing means responsive to said delayed intelligence signals and operative to combine the same to form a scrambled intelligence signal; transmitter means responsive to said scrambled intelligence signal and operative to modulate a further carrier signal, having the same frequency as said carrier signal, with said scrambled intelligence signal and to transmit said modulated further carrier signal; second switching means associated with said transmitter means for controlling transmission, said second switching means being normally in the open position and being responsive to said switching signal to close the same and to thereby cause transmission of said modulated further carrier signal; and means for generating said switching signal connected to said first and said second switching means, said last mentioned means being independent of said modulated carrier signal.

Claim 9

A radio communication interference system for destroying the intelligibility of an intelligence signal modulated upon a carrier signal, said system comprising: receiver means responsive to said carrier signal and operative to demodulate said carrier signal to derive said intelligence signal; first switching means associated with said receiver means for controlling deriving said intelligence signal, said switching means being normally in the closed position for deriving said intelligence signal and being responsive to a switching signal to open the same and to thereby discontinue deriving said intelligence signal; signal delay means responsive to said derived intelligence signal and operative to delay the same by a plurality of different times to provide a plurality of delayed but overlapping intelligence signals, summing means responsive to said delayed intelligence signals and operative to combine the same to form a scrambled intelligence signal; transmitter means responsive to said scrambled intelligence signal and operative to modulate a further carrier signal, having the same frequency as said carrier signal, with said scrambled intelligence signal and to transmit said modulated further carrier signal; second switching means associated with said transmitter means for controlling transmission, said second switching means being normally in the open position and being responsive to said switching signal to close the same and to thereby cause transmission of said modulated further carrier signal; and means for generating said switching signal connected to said first and said second switching means, said last mentioned means being independent of said modulated carrier signal.

Claim 10

A radio interference system in accordance with claim 7 in which said means for generating said switching signal has a duty cycle which is approximately equal to 50 percent.