Friday, December 6, 2013

Re: [Discuss-gnuradio] Need help identifying jammer signal

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On 12/06/2013 11:05 AM, Johnathan Corgan wrote:
> On 12/06/2013 10:48 AM, Juha Vierinen wrote:
>
>> A scope plot of the signal shows something that looks a little bit
>> like frequency shift keying.
>
> Make sure the signal is filtered to the 10K width and attach an FM demod
> block to that (just set the sensitivity to 1.0 for now). It definitely
> looks like 2- or 4-level FSK.

Due to the drift apparent on the order of seconds, you may only be able
to filter down to 20-30KHz. The 'Frequency Xlating FIR Filter' block
would let you downconvert from +166 KHz, filter the signal, and decimate
down further from 1 Msps to something that would be suitable for input
to the FM demod block.

If you want, I could let you upload a capture file to gnuradio.org so
everyone could join the hunt.

--
Johnathan Corgan, Corgan Labs
SDR Training and Development Services
http://corganlabs.com

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