Bug Report - Sound bug on AM when squelsh is activated

[Benoittt]

Hello

 

When i'm using the dongle on AM to listen aerian and I set up the squelsh, I can heard a very bad sound, like speaker turn on/turn off , tac tac tac tactac.

 

Normaly i'm using AGC, i've tried to desactivate it but it changes nothing.

 

I'm on a Debian Squeeze on a Lenovo X61.

 

Some peope encounter the same issue?

[Jasper Ragworth]

Sounds similar to this: https://groups.google.com/forum/?fromgroups#!topic/gqrx/h0iLI2kJSO8

[Benoittt]

Thanks. I will follow the instructions.

[Alexandru Csete]

It could be that the squelch is not good for AM. It was created and
tuned using FM and the Funcube Dongle at 96 ksps. Which dongle are you
using?

I will not have time to look at it for the next 10 days or so. If
anyone wants to try, there is a time constant parameter currently hard
coded to 0.001:
https://github.com/csete/gqrx/blob/master/receivers/nbrx.cpp#L43
Other values may give better results.

Alex

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[Darren Long]

Hi,

I've found that I need to set the audio level for AM to about 6dB lower
than I do for SSB.

For example, if have the squelch on lowest setting (fully open) and I
need an audio gain of +6dB to comfortably listen to an SSB signal on
40m, then I need 0dB audio gain for AM broadcast. At +3dB audio gain,
the AM broadcast station is distorted, and at +6dB, there is no audio
output.

I've had related confusion with AM receivers in gnuradio itself, but I
never figured out what audio gain range was appropriate for AM until I
found the sweet spot in gqrx.

The squelch seems to operate OK on AM for me.

Cheers,

Darren, G0HWW

On 20/07/12 10:58, Alexandru Csete wrote:
> It could be that the squelch is not good for AM. It was created and
> tuned using FM and the Funcube Dongle at 96 ksps. Which dongle are you
> using?
>
> I will not have time to look at it for the next 10 days or so. If
> anyone wants to try, there is a time constant parameter currently hard
> coded to 0.001:
> https://github.com/csete/gqrx/blob/master/receivers/nbrx.cpp#L43
> Other values may give better results.
>
> Alex
>
>
> On Thu, Jul 19, 2012 at 3:02 PM, Benoittt <benoi...@googlemail.com> wrote:
>> Thanks. I will follow the instructions.
>>

>> Le jeudi 19 juillet 2012 13:36:54 UTC+2, Jasper Ragworth a �crit :