Re: AM demodulation

Can you give a little primer on using that PLL tracking?    I would love to use that to just track carriers random frequencies.  For instance 10mhz.  Ultimately I want to track and periodically log and offset from true predicted frequency. Like every 10 seconds.

Bill Dailey

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Be impossible to misunderstand 

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On Oct 28, 2019, at 9:27 AM, Barry Duggan <barry@dcsmail.net> wrote:

Hi Albin and Volker,

I added a PLL Carrier Tracking block to take care of the tuning problem. See the revised https://wiki.gnuradio.org/index.php/File:FunCube_AM.png

Albin, that 'spike' is the carrier! This is AM ;)

Thank you both for your suggestions.
---
Barry Duggan KV4FV


On 2019-10-27 07:13, Albin Stigö wrote:

Hi Barry,

Some thoughts:

You have a large DC spike at the center, try using the frequency xlating

fir filter to tune an offset frequency.

Why don't you decimate at the channel filter?

Try observing the signal at various points using the frequency sink.

Good luck,

Albin SM6WJM

On Sat, Oct 26, 2019, 21:02 Barry Duggan <barry@dcsmail.net> wrote:

Hi,

I've been working on a gnuradio AM broadcast receiver, and have found

that the tuning is very critical to obtaining clear audio. My flowgraph

can be seen at https://wiki.gnuradio.org/index.php/File:FunCube_AM.png.

Are there any alternate demodulation methods which are not so sensitive

to exact tuning?

Thanks,

--

Barry Duggan KV4FV