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Title: Emergency radio frequency warning device
Claims: What is claimed is: 1. A radio frequency safety device comprising means for generating a noise signal having a broad frequency band, means for generating an RF signal, means responsive to an audio frequency signal for sweeping said RF signal generating means through a predetermined band at an audio rate, means for modulating said broad band noise signal with said RF signal, means for generating a carrier signal, and means for modulating said carrier signal with said modulated noise signal to thereby generate a broad band radio interference signal which generates an audible signal when received by a radio receiver, wherein said audible signal is a recognizable reproduction of said audio signal. 2. A radio frequency device comprising means for generating a signal having a broad frequency band, means for generating an RF signal, means responsive to an audio frequency signal for sweeping said RF signal generating means through a predetermined band at an audio rate, means for modulating said broad band signal with said RF signal, means for generating a carrier signal, and means for modulating said carrier signal with said modulated broad band signal to thereby generate a broad band radio interference signal which generates an audio signal when received by an audio receiver. 3. The radio frequency safety device of claim 2 wherein said audio signal corresponds to the signal generated by a siren. 4. The radio frequency safety device of claim 2 wherein said audio signal corresponds to a warning signal. 5. A radio frequency device comprising means for generating a signal having a broad frequency band, means for generating an RF signal, means responsive to an audio frequency signal for sweeping said RF signal generating means through a predetermined band at an audio rate, means for generating a carrier signal, means for amplitude modulating said carrier signal with said modulated broad band signal to thereby generate a broad band amplitude modulated radio interference signal for interfering with the commercial AM broadcast band, said interference signal generating an audible signal when detected by a radio receiver. 6. The radio frequency safety device of claim 5 wherein said carrier frequency is lower than 540 kHz and wherein said audio signal is a representation of an audible warning signal. 7. The radio frequency safety device of claim 6 further comprising a bandpass shaping filter for limiting the bandwidth of the output of said signal generator to substantially the AM and FM broadcast bands. 8. A radio frequency safety device comprising means for generating a signal having a broad frequency band, means for generating an RF signal, means responsive to an audio frequency signal for sweeping said RF signal generating means through a predetermined band at an audio rate, means for generating a carrier signal, means for frequency modulating said carrier signal with said modulated broad band signal to thereby generate a frequency modulated broad band radio interference signal for interference with the commercial FM broadcast band, said interference signal generating an audible signal when detected by a radio. 9. The radio frequency safety device of claim 8 wherein said carrier signal has a frequency lower than the lowest frequency in the FM broadcast band and wherein said audio signal is a representation of an audible warning signal. 10. The radio frequency device of claim 8 wherein said carrier signal has a frequency which coincides with discrete frequency assigned FM bands. Other info: Inventors: Sadler, William S. (St. Paul, MN, US) Application Number: 485761 Filing Date: 1974-07-03 Publication_date: 1976-04-06 Assignee: Primary Class(es): 455/1 340/901, 340/902, 455/102 Other Classes: US Patent Ref:
Other Refs: Primary Examiner: Griffin, Robert L. Assistant Examiner: Ng, Jin F. Attorney: Haynes; James D. |
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