RCTankElectronics. Ian has been the most helpful person I've met through this tanking adventure/misadventure. (I can't stress that enough...great guy!) I bought 1 IBU2 Pro to test. When it worked, I bought another. When it worked I bought 2 more. They are a bit troublesome to calibrate, but once they get going, I like them very much. So, I can only imagine that it's user error at this point. (I did read about the bad ones before I slowly began this experiment). Perhaps someone has some method that I haven't tried or some advice to make these things go. Here's to hoping! Thanks everyone.