PURPOSE: To allow the user to set freely a channel up/down channel selection speed as preference by using a preset signal from a means generating a prescribed preset signal so as to switch a channel switching speed setting data generated by the depression of a channel up or down key into another data.

CONSTITUTION: A voltage produced across a resistor R2 through the current flowing from a voltage source 21 to resistors R4, R2 by closing, e.g., a contact S2 is generated at a terminal P2 via the 3rd port 19. Then a CPU 17 detects a signal caused at any of preset terminals P1∼P3 and decides to which contact the signal corresponds to give a data different from contacts S1∼S3 to a register 26. Thus, the difference between the initial value of a counter 25 and a reference value of the register 26 is varied so as to change the switching speed of the channel depending on the position of the contacts S1∼S3.