- #1
JJBladester
Gold Member
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Homework Statement
How does the stereo light in an analog FM radio turn on when you tune into a stereo station?
The Attempt at a Solution
I know that radio tuners work on the concept of resonance. Current and voltage levels spike up at and near the resonant frequency of a circuit.
My initial assumption would be that there is some kind of switching mechanism that when the voltage or current hits a certain level (at resonance), the switch is flipped and the light is turned on.
In newer radios, I'm assuming the switching would be done by a transistor, but what was used in the older analog radios to turn on the stereo light?