Under our towers, highly selective tuners need to be run either in "local" mode if there is a switch for that, or, with a proper resistor across the AM terminal to ground,
you can reduce the signal on the strong stations. Granted, reduction in the full AM band will result, but you can do this. Another way, believe it or not is to add a "select a tenna" and tune only to what you want, actually detuning all else, or try a terk "advantage" unit. Play with those AND a resistor across the terminals and you may find the proper mix. Works here, but all situations are different. We have only one signal to null at full power, yet maintain a good signal at night for our streaming receiver, a Carver in my office, putting out AM stereo to the 'net listeners.