SOUND SECOND INTERMEDIATE FREQUENCY CONVERSION CIRCUIT FOR TELEVISION SIGNAL RECEIVER

摘要

PURPOSE: To improve a sound buzzing characteristic and to reduce the cost of a television signal receiver mounting the reduced number of used parts. ;CONSTITUTION: A local oscillation circuit 32 in accordance with a PAL-I system, a local oscillation circuit 34 in accordance with a SECAM-D/K system a mixing circuit 20, a band-pass filter 36 and a sound detection circuit 26 are provided. The respective local oscillation circuits 32 and 34 oscillate at oscillation frequencies of 11.5MHz and 12.0MHz, higher than the respective sound second intermediate frequencies of 6.0MHz and 6.5MHz for the PAL-I system and the SECAM-D/ K system by an amount of 5.5MHz which is equivalent to the sound second intermediate frequency for the PAL-B/G system.;COPYRIGHT: (C)1993,JPO&Japio