PURPOSE: To enable the adjustment and measurement of frequency of an oscillation output in use by providing an electroconductive pattern for fetching a part of an oscillation signal near an oscillation circuit to lead it outside through a connector.

CONSTITUTION: An oscillation circuit block 2 is carried on the surface of a printed circuit board 1 and a linear pattern 3 is formed on the rear of the printed circuit board 1 of a first layer near right below. Then, one end of the linear pattern is extended to be connected to a required terminal of a connector 4 carried on the end part of the printed circuit board 1. With such an arrangement, an oscillation output of an oscillation circuit 2 is introduced to the connector 4 through the linear pattern 3 arranged near it thereby enabling the measurement of an oscillation frequency as well as a wave form thereof freely with a measuring device connected to the connector 4. Moreover, there is no direct contact of other patterns with a terminal for the oscillation circuit 2 thereby eliminating the disturbance of application.