Old tvs, how did storing settings work, and what changed in the tv when we tuned a channel?
Tuning with physical knobs generally physically changed the resonant tank circuit by changing the value of either the capacitor or the inductor used in it.

They didn't have to save a channel, the frequencies of all the channels in a region are set by regulatory authorities (e.g. the FCC in the US).


2b. Anything that was saved would likely be saved to an eeprom, not a hard drive. Hard drives are too expensive when you only need a tiny bit of storage.