Radio made with digital circuit ----- am Radio

Radio made with digital circuit, am radio Keywords: radio made with digital circuit working principle The schematic diagram is shown in the drawings. The coil L and variable capacitance C1 constitute a tuning circuit, select the required radio. After the high frequency amplification of the non-door G1-G3, the signal is output by the output end of the non-door G3, and then the capacitance C3 is filtered, and the DC electrical electricity containing the high frequency signal is very clear, it is obvious that it will save it. Secondary tube detection. After the alignment flow of the capacitor C4, there is only an audio signal on the load resistor R2. Then the low frequency amplifies of the non-door G4-G6 is large, and the signal is applied to the base of the triode V by the capacitor C7 to perform impedance transform and power amplification, and the transmitter output signal of the triode is output. Finally, sound is made by the headset. Resistance R6, capacitance C5, and C8 constitute a decoupling circuit to prevent circuit generation of low frequency self-excitement. Here is a 6V power supply to enhance the magnification of the amplifier to high frequency signals. Through the experiment, when the 3V power is used, the amplifier consisting of non-door has almost no enlarged effect on the high frequency signal. In the circuit, the capacitor C2 is a high frequency bypass capacitor for cutting DC, allowing the high frequency signal to pass, the resistors R1, and R4 are the bias resistance of the amplifier. The amplifier access R3 facilitates improving the performance of the amplifier. Components Select G1 to G6 to select non-door HCF4069 or CD4069. The variable capacitance C1 is selected from the CBM-233P. The capacitor varies between 5-141P. The inductive coil L is 10 × 3 × 55 mm magnetic rod with a lacquer line of a diameter of 0.18 mm. The triode V is between 9013 and β at 150-200. The CK uses a switch 3.5mm stereo socket. Power supply 4 sections 5 batteries. Headphones with 32 ohm stereo headphones. Except for electrolytic capacitors, other capacitors use porcelain capacitors. Production and commissioning requirements When the welding element, the component is to be short as possible. After the component is welded, after the inspection is correct, connect the 6V power supply, plug in the headset, and you should hear the sound. Then rotating the variable capacitor C1 should receive the station. The resistance of the resistor R2 is then adjusted. Until the radio effect is best. The radio consumes approximately 15 mA during operation. Finally, adjust the frequency of the radio. Turn the variable capacitance C1 counterclockwise to the top. The position of the moving magnetic rod is received a low-end station. Then turn the variable capacitor C1 clockwise to the top, and the small capacitance above the variable capacitance receives a high-end station. This is repeatedly adjusted several times until the high and low-end radio is received, and then the coil is fixed with the wax.