I believe that you are asking about narrowing the I.F. bandwidth. If you use
narrow filters, this is quite possible. Since FM stereo stations occupy a
150kHz bandwidth, you would be clipping the sidebands, resulting in lost
information. If you are only receiving in mono, this wouldn't be an issue.

Pete

"R J Carpenter" wrote in message
...

"Richard" wrote in message
...

Can you make a circuit that responds only to the wanted
station when it is just fractionally stronger than the unwanted station?

That's called "capture ratio". Better receivers have lower numbers -
smaller difference required to suppress unwanted station. They have
numbers
like a VERY few dB.

To get this you need very flat IF within the passband - no ripples in
response.

A wideband limiter and wide and very linear discriminator.

The National "Criterion" series of tuners from 50 years ago were among the
first to attempt this. IIRC, there were HH Scott tuners like this as
well.

All bets are off if you're trying to recover stereo.

73 de bob w3otc