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4498195 Radio interference detection device for use in a multi-channel access angle-modulation radio system
VI
New
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.
4498194 MULTIFREQUENCY SCANNING RECEIVER WITH PRIORITY FREQUENCY MONITORING Johannes J Vandegraaf assigned to General Electric Company
Patents
ao
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A radio interference detection device for use in a multi-channel access angle-modulation radio system. A detecting system detects a received signal prior to angle demodulation and produces an AM component of the received signal which is then rectified. A determining section then determines the level of the rectified signal for use in detecting interference in accordance with a determination result. The determining section includes an angle demodulator for angledemodulating the received signal, a first comparator for comparing the angle-demodulated signal and the rectified signal, a second comparator for producing the detection signal when the rectified signal exceeds a predetermined level and a gate for passing the output signal from the second comparator only when the angledemodulated signal is smaller than the rectified signal.
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4498197 A scanning receiver is provided with a pause detector which causes the receiver to tune to a priority channel during pauses in the transmission on a nonpriority channel. Ifa priority transmission is present, the receiver remains on the priority channel until the priority transmission ends. If no priority transmission is present, the receiver is tuned back to the former nonpriority channel.
OPTICAL
RECEIVER
David P M Chown, Harlow, United Kingdom assigned to International Standard Electric Corporation
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2
9
4498195 RADIO INTERFERENCE DETECTION DEVICE FOR USE IN A MULTI-CHANNEL ACCESS ANGLE-MODULATION RADIO SYSTEM Tetsuo Ooi, Hiroshi Watanabe, Akio Gotoh, Shuitsu Tsutsumi, Ryohei Oba, Koichi Ito, Syouzi Huse, Tokyo, Japan assigned to Nippon Telegraph & Telephone Public Corporation; Tokyo Shibaura Denki Kabushiki Kais
An optical receiver for responding to optical energy propagating in an optical fibre transmissions path (1) is detected by a reverse-biassed p-in diode (2) which is in series with a forwardbiassed p-i-n diode (3). The junction between the two diodes is connected to the input of an amplifier (4), which feeds on auto-equallzer. The auto-equalizer includes another p-i-n diode (7) which is in series with the signal path, and is forward-biassed. Due to the associated components including resistors (9, 10), the diode (7) passes the same average current as do the diodes
New
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.
4498194 MULTIFREQUENCY SCANNING RECEIVER WITH PRIORITY FREQUENCY MONITORING Johannes J Vandegraaf assigned to General Electric Company
Patents
ao
~
so
A radio interference detection device for use in a multi-channel access angle-modulation radio system. A detecting system detects a received signal prior to angle demodulation and produces an AM component of the received signal which is then rectified. A determining section then determines the level of the rectified signal for use in detecting interference in accordance with a determination result. The determining section includes an angle demodulator for angledemodulating the received signal, a first comparator for comparing the angle-demodulated signal and the rectified signal, a second comparator for producing the detection signal when the rectified signal exceeds a predetermined level and a gate for passing the output signal from the second comparator only when the angledemodulated signal is smaller than the rectified signal.
q
4498197 A scanning receiver is provided with a pause detector which causes the receiver to tune to a priority channel during pauses in the transmission on a nonpriority channel. Ifa priority transmission is present, the receiver remains on the priority channel until the priority transmission ends. If no priority transmission is present, the receiver is tuned back to the former nonpriority channel.
OPTICAL
RECEIVER
David P M Chown, Harlow, United Kingdom assigned to International Standard Electric Corporation
~
2
9
4498195 RADIO INTERFERENCE DETECTION DEVICE FOR USE IN A MULTI-CHANNEL ACCESS ANGLE-MODULATION RADIO SYSTEM Tetsuo Ooi, Hiroshi Watanabe, Akio Gotoh, Shuitsu Tsutsumi, Ryohei Oba, Koichi Ito, Syouzi Huse, Tokyo, Japan assigned to Nippon Telegraph & Telephone Public Corporation; Tokyo Shibaura Denki Kabushiki Kais
An optical receiver for responding to optical energy propagating in an optical fibre transmissions path (1) is detected by a reverse-biassed p-in diode (2) which is in series with a forwardbiassed p-i-n diode (3). The junction between the two diodes is connected to the input of an amplifier (4), which feeds on auto-equallzer. The auto-equalizer includes another p-i-n diode (7) which is in series with the signal path, and is forward-biassed. Due to the associated components including resistors (9, 10), the diode (7) passes the same average current as do the diodes