rtl_fm: degraded demodulation caused by self-introduced DC !?

Hayati Ayguen h_ayguen at web.de
Sat Jul 18 10:15:25 UTC 2015

Hi Nikolay,

i don't see any option to do IQ calibration in rtl_fm !?

As i wrote to Murat, the DC is NOT the LO !
The spectrum already looks clean. I don't have a problem with the symmetry.
The "dc" option does work too late: after demodulation.

kind regards,

Am 18.07.2015 um 12:03 schrieb Nikolay Dimitrov:
> You need IQ calibration.
> When calibrated, spectrum should look much cleaner, signals should
> appear only on 1 place of the waterfall/spectrum display, and the LO
> carrier (the so-called DC) will be much better suppressed, although not
> completely removed (that's why the -dc option exists for the baseband
> processing).
> Regards,
> Nikolay

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