PURPOSE: To prevent a same frequency from being preset by comparing a frequency received at present with a preset frequency.

CONSTITUTION: The communication between a reception frequency storage section 1 and a preset frequency storage section 3 is implemented every time the content of the storage section 1 is changed via a preset comparator section 6 other than write or read of the preset channel. When the contents of the storage sections 1,3 are equal to each other, the content of the preset channel storage section 4 is transferred to a reception channel storage section 2 and to a display section 5, in which the content is displayed.