PURPOSE: To achieve a smaller size with the curtailment of a man-hour of adjustment, by a method wherein a coaxial cable with the length enough to shortcircuit for an undesired wave is connected at a measuring point between function blocks of an electronic circuit to make a terminal for adjusting test so that the coaxial cable concurrently serves as a filter.

CONSTITUTION: A mixer 1 into which are inputted an input from a connector CN-1 and an output of a local oscillator 2 and a pre-intermediate frequency amplifier 3 connected thereto compose a first function block. An attenuator 7, a band pass filter 8, a variable gain intermediate frequency amplifier 9, a detector 10 and the like, which receives an output of the function block as input, compose a second function block. Then, a coaxial cable with a specified length is connected to a connection point of the function blocks as measuring point. Thus, the coaxial cable is made to function as filter, thereby achieving a smaller size of the circuit while eliminating the switching of a measuring terminal.