Question

The "over-the-air" television channel 13 operates between frequencies 210 MHz and 216 MHz, with the video and audio using different parts of this frequency range. To watch (and listen) to the channel properly, the tuner circuit in a television must resonate in the middle of this range (213 MHz) and produce a current over the whole range of at least 50% of the peak current at resonant frequency.

A particular television tuning circuit is built with a 17.3 pF capacitor, a variable inductor, and a variable resistor. What value should the resistor be in order for the current at both 210 MHz and 216 MHz to be at least 50% of the current at the resonant frequency?

Hint:You'll have to first calculate the value of the inductor so that the television tunes to channel 13.

Answer 1