If you have reason to use the NB/ANL, then use it. If you haven't a reason, then don't. Just depends on the noise you're trying to get rid of.
RF gain. Personally, I like it all the way UP. That tends to make the weak ones easier to hear. It also increases noise. So, if you don't wanna listen to the noise in the background with no signal, use the SQL to stop it. Noise levels change, so that SQL will change, the setting varies with the noise. The SQL does NOT do the same thing as the RF gain control does. That RF gain controls sensitivity. The SQL, in effect, just turns off the speaker so a stronger signal has to be present before you hear anything. If you decrease sensitivity, that 'stronger signal' has to really be stronger to be heard. Think of it like decreasing the sensitivity in your fingers. At some point they get numb. You won't know you're being cooked till you smell stuff burning, you know?
The whole idea is to make things comfortable to listen to without a lot of 'extra' noise. Adjust to suit your self. That's what's 'best' for you.
- 'Doc