I believe he is talking about adjacent channel signals which are much
stronger than the desired and trying to see if there is a way to "fix" that.
Capture does not apply for this situation. Capture is a co-channel effect
and is better the wider the whole system is, not just the IF.

--
Steve N, K,9;d, c. i My email has no u's.


"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