sorry but i have to correct that statement. all airplanes make wake turbulence. the only time it isn't noticeable is on take off or landing roll. it starts at the point of liftoff and stops at the touchdown point. however, it is at its strongest when the plane is heavy, clean,(no flaps or gear) and slow. the contrails you see coming off of full scale planes is in a sense wake turbulence. it comes from the two halves of the airflow going over the wings coming together. the pressure must equal to the normal outside pressure. Bernoulli's principal of lift is that the higher airflow speed over the top of the wing is at less pressure than that going around the bottom half. but they must equal when they are off of the trailing edge of the wing.
and yes, prop wash will get your models too!!!

sorry for the buzzkill, but just wanted to clear that up if anyone got confused.