RTL2832U FIR filter

Francesco Gugliuzza f.gugliuzza at hacklabproject.org
Sat Jul 14 23:22:37 UTC 2012

2012/7/14 Michael Karcher <osmosdr at mkarcher.dialup.fu-berlin.de>:
> I furthermore found out that this is not the only filtering going on in
> the RTL2832 chip in SDR mode. There seems to be a second anti-aliasing
> filter before the DAC, making signals disappear that are at frequencies
> above 0.7 times the sample rate (in the baseband), even if the
> programmable FIR filter lets them pass.
That's probably an effect of the E4000 output filter. You can see the
filter bandwidth being set in the tuner initalization code.

Francesco Gugliuzza
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