As you may have seen in my on
air tests I just posted, I have no problem with low signal levels, however, there is an active hardware AGC which may be causing you troubles. If you have a strong signal in the analog passband of the tuner it will drive the gain down and the weaker signal you are trying to receive will become noisy. You can see that in all
3 videos which show an EzCAP666 with E4000 tuner in action.
I don't know if this AGC is in the RTL chip or the E4000 tuner. I suspect it is in the tuner.
Alex