| 摘要 |
The signal decoder automatically monitors the transmission of a radio broadcasting station. For this purpose, it is connected to the AF output of a radio receiver or else to the output of an audio tape recorder, which reproduces a recorded transmission. From the HS, the signal decoder decodes the identification of the programmes and stores them together with the time of day. The main memory of the device takes at least all the identifications which are received within 31 hours. After that, the gathered data are written to an 8" floppy disk in IBM-3748 format. The floppy disks to which the signal decoder writes can be read and evaluated directly on IBM systems. The signal decoder is constructed in a 19" rack of 3 vertical modules (outside dimensions W x H x D 496 x 180 x 400 mm). On the front panel are the on-off switches and five buttons for operator control, apart from seven displays and the floppy disk drive. On the rear of the device is a diode bush as AF input, the mains connection (inlet connector for non-heating appliances) and a mains fuse. The main component of the signal decoder is a microprocessor Z80A with 64 kbyte random-access memory, which controls the function of the device. The operating program, which controls the function, is in a read-only memory. The microprocessor decodes the received information, stores it and controls the writing to disk. In order to be able to decode the HS reliably, the signal decoder has a complex input part which comprises a combination of filter circuits and a phase-locked control loop.
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