A radio tuner is built by connecting an L=0.44 mH inductor and variable capacito
ID: 2217819 • Letter: A
Question
A radio tuner is built by connecting an L=0.44 mH inductor and variable capacitor in series with an antenna. The driving voltage is provided by the radiowaves that pass through the antenna, and the total internal resistance of the circuit is R=1.8 Ohms. C)If another station operates at 510 kHz with the same amplitude at your location, what is the ratio of the output voltage due to this background signal to the output of the signal for which the circuit has been tuned? The output voltage is the voltage across the capacitor. D) Find this same ratio if the other station operates with the same amplitude at frequency 555kHzExplanation / Answer
The series tuned circuit is able to give a very large voltage step-up if you have a low impedance source driving a high impedance load. The circuit has no power gain, so it converts a low voltage at high current to a higher voltage at a lower current. This depends for its success on the antenna and also it will depend on the frequency for a given antenna. I will attach a possible circuit. For the circuit to be of much use, I have shown a tapped inductor which may allow for the use of practical antennas. The series circuit, though, is just the inductor and the variable capacitor.