I picked up eight National plug-in coils today. 50-100 KC 100-200 KC 180-430 KC .48-.96 MC 1.7-4.0 MC 3.5-7.3 MC 7.0-14.4 MC 14-30 MC There are no markings on the face plate or aluminum shells to help determine what National radios they match. Is there a way to tell? 73, gary