As you can see in the following picture, with my first assembly I received many signals in the full 0-32 MHz band simply connecting my EFLW antenna directly to the analog input. 

I'm pretty sure that a few of these signals are entering the receiver from the 2nd and 3rd Nyquist zone but I'm not sure because I cannot demodulate them at the moment. 

Anyway in my opinion this first result encourages me to go on! 

(Y-axis not in scale)