The 'Power Squelch' block in GRC is my favourite and I would recommend
using this one.

Have a look at the following GRC flow graph for a working example that uses
the power squelch block:

https://raw.githubusercontent.com/m0mik/scanoo/master/apps/scanoo.com_rx.grc

Note that the 'Ramp' setting is the number of samples it takes at the start
and end of a detected signal for the volume to go from 0% to 100% and 100%
to 0%, and the 'Alpha' setting is the signal average alpha just like in the
FFT WX GUI widget. 1 disables the averaging and will give you the fastest
cutoff at the end, however if you have signal flutter then the audio will
be choppy.  I'd recommend using between '0.01' and '0.001' in the power
squelch block for the 'alpha' setting.

Mike

--
Mike Jameson M0MIK BSc MIET
Ettus Research Technical Support
Email: [email protected]
Web: http://ettus.com


On Sun, Jul 13, 2014 at 12:05 AM, <[email protected]> wrote:

> I've deployed a gnuradio application which records a morning maritime
> radio program in a Caribbean community. The recording can be played back
> online for people who missed the 'news'.
>
> The application works famously. However, I've got a request for an
> enhancement that comes up a lot! Everyone is used to hearing the 'ksht'
> sound after the mike is unkeyed. However, the squelch function I use in
> GnuRadio 3.7.1 doesn't seem to have a setting which affects how quickly the
> squelch gate closes (its instantaneous). There is an Alpha and a Ramp
> function, but they don't seem to affect the result (wouldn't expect Alpha
> to).
>
> Does anyone have any insight into the code for this block?
>
> Jim
>
>
> _______________________________________________
> Discuss-gnuradio mailing list
> [email protected]
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
>
_______________________________________________
Discuss-gnuradio mailing list
[email protected]
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

Reply via email to