I've tried different crystals, transmitter, rx18....there all no good....swapped then with 2 known good tanks, and nuthin....I'm not saying that they deliberatly scammed Me...I just want them to make things right...I forked over $138 for Metal gearboxes and RX18 IR upgrade kit...I never receved the gearboxes and none of th RX18 stuff works.....What would You think??