Right - the distance you can communicate is mostly determined by the antennas (both ends) and the frequency. Modulation mode does play a part because some modes are more efficient than others, e.g. a good SSB transmission concentrates all the transmitted energy into intelligible vocal frequencies while AM wastes a lot of energy on a carrier wave and a duplicate of the audio. FM has superior noise rejection but very poor weak signal performance.
They get mixed up a lot though, because AM is used on the short, medium and long-wave broadcast bands and FM on the VHF broadcast band, so terms like "FM radio" or "the FM band" are used.
More to the point, can they not control vehicles using FM?
Becoming increasingly cynical, I am assuming that AM is required either to control your vehicle centrally or to pass information about you to the powers that be.
Agreed, but maybe they have a reason to prefer AM? Perhaps th FM spectrum is full. Maybe they prefer lower frequencies so they need fewer transmitters/repeaters?
This is false. At any given frequency/power the type of modulation (AM or FM) has zero effect on the distance the the signal travels.
I think she's confusing modulation type with frequency. Low frequency signals travel further than high frequency.
This is why we need engineers in government and not ignorant politicians.
Right - the distance you can communicate is mostly determined by the antennas (both ends) and the frequency. Modulation mode does play a part because some modes are more efficient than others, e.g. a good SSB transmission concentrates all the transmitted energy into intelligible vocal frequencies while AM wastes a lot of energy on a carrier wave and a duplicate of the audio. FM has superior noise rejection but very poor weak signal performance.
They get mixed up a lot though, because AM is used on the short, medium and long-wave broadcast bands and FM on the VHF broadcast band, so terms like "FM radio" or "the FM band" are used.
How much is going into her pockets to push this shit?
More to the point, can they not control vehicles using FM?
Becoming increasingly cynical, I am assuming that AM is required either to control your vehicle centrally or to pass information about you to the powers that be.
[They] can control your vehicle with whatever signal they choose. It's only a matter of matching the receiver to the transmitter.
Agreed, but maybe they have a reason to prefer AM? Perhaps th FM spectrum is full. Maybe they prefer lower frequencies so they need fewer transmitters/repeaters?