It is not some thing I could do myself, but maybe start with a radio out of its case  and improve the ferrite antenna, and maybe the tuning cap?  I thought I saw the AF amp in that chip is rated at 500mW, and the SONY radio spec is for 200 mW. It could be the chip can operate on a voltage higher than 3V?  If so it might work better. The 200 mW drives a Klipschorn very nicely, but other circuits may or may not work better at a higher voltage if the chip can do it. I think in the files section there was a Helenized receiver article which did just that sort of thing. - FARMERIK