Amplification-hybrid antenna amplifier circuit

The schematic diagram of the antenna amplifier in the amplification-mixing mode is shown in the figure below. The TV signals of channels 1 to 12 are input at the VHF input end, and a simple low-pass filter is formed by L1, Cl, and L2 to filter out the TV signals after channel 12, and send them to the signal input end of IC1 for about 20dB amplification. The amplified TV signal is output through capacitor C3, mixed with the UHF signal through the low-pass filter of L3, C4, and L4, and then sent to the TV signal output end. The TV signals of channels 13 to 57 input at the other UHF input end are formed by a simple high-pass filter of C5, L5, and C6, which only allow the signals of channels 13 and later in the UHF band to pass through, and then added to the signal input end of IC2 for about 20dB amplification. After output, it is mixed with the VHF TV signal through a high-pass filter (C7, L6, C8) and sent to the TV's Ou Rui. The power supply of this circuit is supplied to the amplifier after voltage reduction by transformer T, rectification by Ul, filtering by C14, and voltage stabilization by 1C3. LEDI and Rl are power indicator circuits.