[Elecraft] [K3] FM and AM Bandwidth

[Lyle Johnson]

Hello Jack!

> No, Carson's rule is occupied bandwidth = 2*(deviation + maximum 
> modulating frequency)...

You are correct. Thank you for pointing this out.

This is all the more reason why we can't increase the FM audio passband. 
  In fact, we limit the upper end to 2.8 kHz and rapidly roll off 
response to higher frequency audio components.  Fortunately, even with 
pre-emphasis, the highest frequency components of a typical voice don't 
have a lot of energy at the highest frequencies, so the resulting 
occupied bandiwdth is probably a little less.

Those of our customers in areas with tight channel spacing need to 
reduce their deviation consistent with common Amateur FM practice in 
their area.  Use CONFIG:FM DEV to set the peak deviation.

73,

Lyle KK7P