Re: [Discuss-gnuradio] Squelch block, AGC function and scanner example

[Martin Dvh]

Eric Blossom wrote:
> On Tue, Jan 18, 2005 at 08:36:07PM +0100, Martin Dvh wrote:
>
> > > -----------------------------------
> > >
> > > Is there a way to access the magnitude of the channel to setup a 
> > > squelch function?  How would that work with this chain of blocks?  Is 
> > > there another block that would go in the chain to zero the output if the 
> > > I*I + Q*Q of the signal is below a threshold?
>
> Martin, you rock!
>
> Thanks for cranking out all this code!
>
> Eric
Well, there is more to come.
I am also working on some fft spectrum_magick code.
This will be a scannerlike app or block with which you can scan the entire 
rf-spectrum and  you will get the entire static rf-spectrum (averaged
over a specified time-period)
It will make a list of the static spectrum peaks in there.
But it will also find the frequencies which have sometimes a peak and sometimes 
not and make a list of them.

I hope also to find a way to determine what kind of signals they are (FM, AM, 
TV, FSK)

This way you get a list of everything there is to receive with your current 
frontend.

I am also still working on my tvcard as frontend hardware-modifications and 
driver.
This will make a standard bttv tv-capture card usable as gnuradio frontend 
(both tuner and ADC)
You could also combine the tuner in the tv-card with an usrp/mc4020 or a 
microtune tuner with the bttv ADC.

I am receiving and demodulating signals but it still has a lot of interference 
and some timing problems.
I think I need to buy/design/built a better IF filter and amplifier for this to 
work better.

Greetings,
Martin