Now, let us study the first tube in details. It is set up as an oscillator and mixer. Look at the osc coil with a tap. The Cathode goes to the tap to gets its ground. But the long side of the coil goes to a grid.So, the tube goes into an oscillation. The frequency is controlled by a variable capacigor anged with the tuner to the antenna coil. The antenna coil is fed into a grid to mix its signal with the local osc. The plate is in series to the primary of the first IFT. The second tube is a straight forward RF amp which amplifies only the 455 Khz intermediate frequency. This makes the radio selective.