I have a Futaba 4PKS-R that has a port on it that outputs PPM(looks like a 3.5mm headphone jack). I have a PPM to USB adapter and it works really well. I like it because it allows you to access all of the channels of the radio, compared to the 2 of the VRC adapter. I bound a button on my radio to the marshal car command in VRC so that I don't have to take my hand off the transmitter to marshal my car.