| 摘要 |
PURPOSE: To save facilities and improve the FM precision of the composite signal generating device by providing a composite modulated signal generating means and a single high-purity radio frequency source which generates a composite RF signal with its output, and generating a composite signal by using only a single signal generating device. CONSTITUTION: A test signal is generated by two audio frequency modulating processes of adjacent channels which are 12.5kHz away at a frequency of, for example, 1.7MHz. A test signal generating device 50 is equipped with a composite frequency modulated signal generating device 51, whose output is connected so as to modulate a high-purity RF source 52; and the output of the RF source 52 is the test signal. Other variables such as a frequency interval and relative electric power of two channels are received by the composite FM signal generator 51 from, for example, an operator adjustable controller as an input 54. Therefore, the contiguous channel performance of an actual radio receiver in a speech state is subjectively evaluated and utilized. |
