Success!! I switched the crystals in the 4chan Skybus and Hawk Sky and tried as above (luckily the crystals are not soldered in). The Hawk Sky airplane worked perfectly with the Skybus's Tx using the Hawk sky Tx crystal. I'm assuming I have a defective 72.830 Tx with my new Hawk Sky. So sad. The plane looks great and I even reinforced the clevises and control horns already. Anyway I can send back the defective Tx if you want to replace it. Thanks for all your time and assistance. Best regards for great service after the sale. Cheers, Mark Taylor