| 摘要 |
PURPOSE:To shorten a search activity time greatly by providing a receiving antenna with sharp directivity in a swiveling state, and detecting a direction where a radio transmitter held by a crewman is present. CONSTITUTION:A receiving antenna 13 having sharp directivity is rotated by a driving device 26, and an antanna angle detection part 27 and an antenna angle display part 28 are provided to display a high directivity direction of the antenna 13. At the same time, an FM-modulated electromagnetic wave received by the antenna 13 is amplified by a high frequency tuned amplifier circuit 14, whose output is mixed with a local oscillation signal generated by a local oscillating circuit 15 by a mixing circuit to obtain an intermediate frequency signal. This signal is amplified by an intermediate frequency amplifier circuit 17, whose output is displayed on an electromagnetic wave intensity display part 28 together with an antenna angle; when the output of the circuit 17 is maximum, the presence of a transmitter is known from the antenna angle. |
