Multi-standard television receiver circuit - automatically switches to UHF or VHF operation changing both IF and output stages

摘要

The television receiver circuit is able to re-form from the signal the images transmitted by systems using different standards. The received waves are sent to a tuner switchable to UHF on VHF, powering video and audio outputs. The receiver includes a synchronising device synchronising the difference existing between the carrier wave and that of the image carrier wave. The device automatically switches to the appropriate standard. The automatic switching circuit simultaneously operates both the intermediate amplifier stages and the output stages. The receiver includes both frequency and amplitude modulation demodulators the system has amplifiers suitable for all standards used for colour transmission.