| 摘要 |
PURPOSE:To attain the judgement of the propriety of radio wave state by providing a meter changeover circuit outputting an output of a reception circuit to one of two level meters depending on the result of decision of a carrier detection circuit and holding the level just before the changeover to the other level meter. CONSTITUTION:The titled transceiver is provided with a reception circuit 2 amplifying an input radio wave and selecting an objective reception frequency, a carrier detection circuit 4 inputting an output of the reception circuit 2 to decide the presence of a carrier from the transmission side, the two level meters 5, 6 and a meter changeover circuit 3 outputting an output of the reception circuit 2 to one of the two level meters and holding the level just before the changeover to the other level meter. When the reception circuit 2 decides that the radio wave from a transmitter is being received, an output of a carrier detection signal is brought into logic 1 and into logic 0 in other cases. Then the intensity of an input radio wave is displayed on the level meter 5 at carrier reception, the intensity of the input radio wave at carrier non-reception is displayed on the level meter 6, that is the intensity of noise radio wave is displayed. Thus, the propriety of the radio wave state is judged by the user. |
