| 摘要 |
PURPOSE:To check operations of the whole of the device including the modulating and demodulating circuit of a radio equipment, by constituting the device so that the transmission signal can be converted to a receiving frequency and be turned back and be received by the station itself. CONSTITUTION:A turning back command is sent to an I/O 4 through a data bus, and a processor 1 decodes this command, and a driving signal is sent to a tone oscillator 5, and transmission and receiving channels to be tested are designated here, and a transmitter 6 is turned on. The output signal from the transmitter 6 is sent to a mixture 11 through a coupler 9 and is mixed with the oscillation frequency of an oscillator 12 and is converted to a receiving signal of the station itself and has the level adjusted by an attenuator 13 and is given to a receiver 7. This output signal is amplified by a tone receiver 8 and is sent to the I/O 4. This receiving tone signal and the transmission tone signal are collated with each other by the processor 1 to discriminate normality or abnormality of operations. |
