This NuTone NM Series AM FM Antenna Board was standard on the NM100.
You would have to purchase it separately for the NuTone NM200
Since the NM100 was primarily a model that was designed to update older 3-wire NuTone Intercom Systems. there was an assumption the the original AM FM Dipole Antenna would be reused (instead of the new antenna included with the new wall housing).
This Antenna board allowed the origianl dipole antenna to be connected - to the 2 right-hand screws (for FM) and a small jumper wire would be connected across the 2 left-hand screws (for AM)
This would have been the same for the M&S Syetms DMC3-4 - I think
This antenna board was not inlcuded with the NuTone NM200 or the M&S Systems DMC1