I'm doing some research and stumbled on this information: AN/ARC-2, built by Collins and by RCA, first acquired by the navy in 1944, 40 watts, 2-18 MC, 8 preset channels. AN/ARC-2 (XN-1), built by Collins, first acquired by the navy in 1943, 50 watts, 2-9 MC. Anyone have any other information on these variations? 73 Dave S.