"Tony" wrote in message
...
I'm still searching for another fast and simple solution to push my tuner
to
4 o 5 Khz.

I assume you mean MHz.

What do you think about modifing the local oscillator (whe you found it in
the pcb)? Due to high frequencies, it is probably a simple air coil. So I
can insert ferrite rod inside it to rise up inductance (and lower the
freq)... or i can cut off a spire....
Or modifing the capacitance of the tuning capacitor? I can add another cap
in parallel with it, exploing that parallel caps drop down the
capacitance...

It might work, but sensitivity will be poor. As you go up in frequency
band noise drops, so you'll need more gain. Also AM receivers are designed
mainly for strong local signals so might not be particularly sensitive to
start with.

Stick with the converter idea.

Peter