That's one of the drawbacks of RF. You have to have their controller hooked up even if you want to use your own radio. Nothing like more clutter around the computer desk. Apparently the technology to put a tiny chip in a USB cable rather than the controller is beyond their engineering prowess.[]
Get a different and newer sim that doesn't require a proprietary controller. There are quite a few sims to choose from. Check the other threads here and on other RC forums.