Re: AM demodulation

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
>>
>>