I have 2 R-390A's: one is a Collins contract and all Collins modules I = bought almost 19 years ago and the other is a Motorola, with all = Motorola modules I bought 15 years ago. They worked fine when I bought = them and they still work just as well. There was nothing replaced in = them since I got them. BTW they came to me with the original meters and = covers. 73, Meir WF2U Landrum, SC