| 摘要 |
PURPOSE:To simplify the constitution of a device, by setting a signal transmitted from a trawlnet to a period of multiple relation, usually making it synchronize with a long period at the side of a ship, and switching it automatically when a pulse of a short period has been detected. CONSTITUTION:A signal is usually received by making a receiver 1 synchronized with a long period of a signal which is transmitted by multiple relation. A synchronizing signal is separated from an output of an amplifier by a synchronizing detector 5. Frequency of a long period is generated by a frequency-divider 7 by dividing the frequency of an oscillator stabilized by a synchronization repeating period generating circuit 6, and generating the same frequency as a short period of the transmission part. Frequencies of a short period and a long period, generated by the circuits 6, 7 are inputted to a gate pulse generating circuit 10 for a short period synchronizing signal expected position, the output is inputted to a coinciding circuit 11, and when it has been synchronized with an input from the synchronizing signal detector 5, a prescribed number is counted by a counting circuit 12, and a signal processing circuit 3 and a recording circuit 4 are made to react in a short period through a signal switching circuit 8 and a timing pulse circuit 9. In this way, a signal is received by switching it automatically, by a simple device. |
