[Biggles]

I once tried a ZN414 to convert an FM only radio scanner into an AM/FM model, way back in the eighties. It took a sample of 455KHz IF signal from the IF chip, before the limiter, and demodulated it. It didn't have the benefit of AGC and used to overload and "flatten out" on large signals, but it worked after a fashion. Neil; The double tuned RF input circuit I had in mind was to top couple two ganged tuned circuits with a low value capacitor. I thought this may sharpen up the selectivity a bit but probably not by much.
Alan.