Re: [Discuss-gnuradio] FM Modulation problem/question

On Mon, Jun 26, 2017 at 10:07 AM, Brashendeavours <brashendeavours@gmail.com> wrote:

Where my results differ from what I expect, is approximately above 100Hz. Using an baseband of 1200Hz, I no longer get a signal sweeping from -ive to +ive, I get [a constant frequency of 1200Hz on the waterfall](http://imgur.com/BqGsRtK), and aliased multiples.

I believe that my sample frequency of 48000 is sufficient as my mf is 2400, and baseband is 1200.

  

BW is (2 * (1200 + 2400)) = 7200Hz

Nyquist is 2*BW = 14400Hz

So, what am I doing wrong?  Thanks in advance!

You're not doing anything wrong, and those are not aliases. They are the sidebands which result from frequency modulation.