Channel selection control system for frequency synthesizer receiver

Abstract

Abstract PURPOSE:To realize a channel selection system which can detect easily and rapidly a broadcast wave exceeding a preset reference level among broadcast waves on a broadcast system which broadcasts the same broadcast contents by several broadcast waves. CONSTITUTION:PLL synthesizer part 1, switches SW1 and SW2 selecting several channels with the same broadcast contents, and automatic detection switch SW3 are provided. Further, ROM1 and ROM2 stored with data signals corresponding to broadcast waves of the same broadcast contents, clock generator CK supplying clock pulses to counter CNT, and comparator COMP making an amplitude comparison between received signals from reference signal generating circuit VR and waveform shaping circuit S are provided. When switches SW1 and SW2 are turned ON and automatic detection switch SW3 is also ON for automatic detection, a signal exceeding a fixed level is selected among radio waves of the same broadcast contents and then applied to counter CNT and an address corresponding to the broadcast wave is supplied from counter CNT to ROM1 and ROM2, so that synthesizer part 1 will make automatic channel selection.

Inventors

• 👤 Kikuo Usugoromo

Bibliographic Details