| 摘要 |
PURPOSE:To reduce multi-bus noise with suppressing noise occurrence on a scope in a monoral mode by storing an antenna of the second grade input level other than the antenna which is of the maximum input level and switching two antennas by every drop of the input level in a sound multiplexing mode. CONSTITUTION:An SIF from a TV receiver 11 is inputted to an SIF level detector 15 and the drop of an input electric field is detected. A control circuit 21 separates, with receiving the signal through an AND gate 20, the first grade antenna which is connected until now and controls an RFSW circuit 22 to connect the antenna of the second grade level replacing the first. And only in the sound multiplexing mode such as a stereo (ST), a bilingual (BIL), by adding the ST or the BIL from the TV receiver 11 to the AND gate 20 through an OR gate 19, and AND gate 20 is opened/closed to perform a diversity operation between V.SYNC-V.SYNC.
|
