Re: FM stereo receiver distortion

[Jeff Long]

If there's no filter inside "WBFM Receive PLL", place one before it. The example in gr-uhd has a 400 kHz filter there.

On Tue, Jun 16, 2020 at 8:46 PM Barry Duggan <barry@dcsmail.net> wrote:

Hi,

I have a broadcast FM (mono) receiver which works well, with good audio
and clean traces in the Time Domain. See
https://wiki.gnuradio.org/index.php/File:USRP_FM_fg.png

Then I made a stereo version. See
https://wiki.gnuradio.org/index.php/File:USRP_FM_stereo_fg.png  Using
it, the sound has a distortion but does not have any audio underruns.
The traces in the Time Domain have a lot of "fuzz" (noise?).

Do I need a filter? If so, would it come before or after the WBFM
Receive PLL block?

Once I have a good design, I will use it as an Example Flowgraph.

Thanks for your help.
--
Barry Duggan KV4FV