OH GOD!!! HOW FOOL I AM!!!!
I made this circuit almost 5 months ago and it was not working. I spent almost 10 days to design its layout on rough note, to design layout on computer, to make PCB, to drill and to solder. I had downloaded all needed datasheet too. I was VERY careful to make better circuit like professional! But today I found that I soldered MPSA18 in worng way!!! Wufff!!!! How non-sence I am!!! What happens to MPAS18 if I fed 12V to its base, emitter is same as emitter and collector is Audio IN (my worng connection), on this circuit? Is it damaged? If it is, I will change another MPSA18.
However I want to modify for better AM detection as you said before. Look at my previous post and suggest me please!