AM and FM

[kermit911]

Is AM more powerful the FM?  as far as distence.  Will AM travel farther then FM?

Thanx

[fo3nix]

it's not more powerful, its just the frequency that is different.

due to a smaller wavelength, FM will be more easily-blocked by hills and the like. AM will thus travel further, but only because its less-easily blocked.

[OBonio]

I was under the impression that they are two different types of broadcast. AM is amplitude modulation and FM is frequency modulation. Traditionally, AM has been broadcast at lower frequencies than FM, but this doesn't have to be. They can be broadcast at the same frequency. This being so, I think they would both reach as far as each other if used on the same frequency.

I stand to be corrected on this though!

[jake-the-peg]

The difference between AM and FM is in the way the information is encoded into the signal.

In AM the peaks and troughs are slightly higher or slightly less and it's these deviations which are stripped out and give you your radio program.

In FM the wavelength varies slightly about the signals frequency and these variations carry the information.

Because radio waves loose power easily passing through obstructions it means that you get poor reception in AM in cars because you are constantly getting variations in the strength of the signal and in AM that strength is where the information is encoded.