[BC] AM Fidelity vs FM fidelity

[Broadcast List USER]

Let's look at this from a practical standpoint, rather than the theoretical.

An AM transmitter into a dummy load can pretty much have a 50 Hz to 20 kHz bandwidth.

Yes, other than plate modulated transmitters can have an extended low end.  Many transmitters, including plate modulated transmitters can go  
up to 50 kHz.

On the other hand FM transmitters always can extend down to 50 Hz. Many go to 20 kHz. Without a stereo generator, most can go down to zero Hertz.

On the high end, FM transmitters can to to 100 kHz, and this is not a practical limit, but a legal limit.  They can go higher.  It is only the Stereo Generator that limits the high frequency response to 15-18.5 kHz.  A mono station can have "audio" response to 100 kHz. This means FM has a wider frequency response than AM.

More to the point, a mono FM station with 100 kHz is LEGAL.

An AM station cannot legally transmit audio with a 50 kHz bandwidth. Or 20 kHz.  Or 15 kHz.  Or 10 kHz.

Do you get it?

It really doesn't matter what is theoretically possible.  We are well beyond that today.

Europe has 9 kHz spacing, but they don't pack the stations as tightly.  The MW stations sound nearly as good as FM.  It is only impulse noise that makes the difference.  Been there, heard that on my Sony 2002.

Richard and Leonard are partially right, as long as you force FM to run Zenith Stereo, and don't push NRSC on AM MW transmitters.  If you  
consider both, FM wins.

--chip

From: RichardBJohnson at comcast.net

>I will repeat for the third time:
>
>"My statement, as was Kahn's, was about Amplitude Modulation. It was not about a particular implementation and was, in fact, the reason why I spent so much time, effort, and money perfecting a specific implementation."
>
>The link provides information about AM and all the 'C' source-code (for someone who wants to learn) for generation and demodulation of Amplitude Modulation from a pure mathematical standpoint without, BTW, using funny Greek symbols that mathematicians sometimes use to hide the simplicity of their work.