Final answer:
To calculate the needed local oscillator frequency for receiving an AM station, one must first determine the carrier frequency, then theoretically calculate the modulation index, and apply the formula FLO1 = FIF + (Modulation index × Carrier frequency), though in practice the modulation index is often not used for calculating LO frequency in AM radio.
Step-by-step explanation:
The student's question pertains to determining the correct local oscillator frequency (FLO1) to shift AM station frequencies to an intermediate frequency (FIF) for radio reception. To accomplish this, the carrier frequency must be known, which is the basic frequency of the station before modulation. The modulation index, which represents the ratio of the amplitude of the modulating signal to the amplitude of the carrier wave, must also be calculated, although in most AM systems, this is not needed for frequency conversion. After finding the carrier frequency and modulation index, you apply the formula FLO1 = FIF + (Modulation index × Carrier frequency) with the assumption that the modulation index's effect on FLO1 is minor and can often be ignored in practice for AM radio systems. Lastly, the antenna length should be adjusted to 1/4 the wavelength of the received frequency for optimal resonance. Please note that in a practical context, the modulation index is not typically used in calculating the LO frequency for AM radio receivers; the LO frequency is generally calculated by simply adding or subtracting the intermediate frequency from the carrier frequency.