AM antenna

Amplitude modulation antenna has special 2 pins coupler behind of Boom box system running in my laboratory, so conventional loop antenna required to connect coupler with some modification.
Seeking about the small coupler, I found it out on some printed circuitry board in my junk box but for 3 pins, could I establish the AM antenna coupling safe by cutting out 1/3 of them.
The main reason for listening AM channel is Radio Athletic Program at 6:30 on 666 kHz in NHK, as an usual manner tuned on NHK FM after that.