The power supply end of the tuner is generally marked with VCC. The specific voltage is related to the operating tuner. Trademarks of tuner are generally available, and common ones are. 12 volts, 9 volts and 5 volts. And tu. Or BU, the terminal is a channel tuning terminal, and the general voltage is 0 ~ 30 volts, which is related to the channel being watched and is not fixed. AGC and AFC are automatic gain control and automatic frequency control terminals respectively, and their voltage is related to VCC, which is generally half of the power supply. VL, VH and U are frequency band terminals respectively, if you want more detailed information. Tell me the detailed model of the tuner and I'll send it to you.