| 摘要 |
PROBLEM TO BE SOLVED: To easily understandably display a free channel by discriminating the reception states of all channels, detecting the free channel and controlling display means for the plural channels by the detected output. SOLUTION: When the command signals of free channel display are outputted to a control part 4 by a free channel display command switch, the control part 4 performs control to search the channel in a reception circuit 2, sampling- processes the reception states of the respective channels, discriminates the presence/absence of respective channel reception signals and detects the channel without the reception signals as the free channel. Further, channel identification information stored in a memory 6 is read by the control part 4 and display drive signals based on the identification information are supplied from the control part 4 to the respective LEDs for channel display of a display part 5. Then, the LED for the channel display corresponding to the free channel is lighted and the LED for the channel display corresponding to the channel in use is turned off. |
