APPARATUS FOR DISCRIMINATING MAGNITUDE OF TV SIGNAL

摘要

A tuner(10) selects a high frequency of the desired channel among a few high frequencies induced at an antenna. It converts the frequency of the selected signal into an amplification efficient intermediate frequency signal. For this, either a rotary channel converter of a local oscillating circuit is used, with a coil exchange of high frequency tuning circuit and a local oscillating circuit can be mode, allowing the selection of desired channel. The signal of selected channel will be transferred to the next block(20). The intermediate frequency amplifier(20) enlarges the selected signals of the intermediate frequency as high as required and the enlarged signals are transferred to an image signal processing circuit and an ADC(30).