Front-End Vibration on Highway

[LarryGreen]

My SVX rides fine on the highway until I turn the wheel right or left. As its being turned, there will be vibration at the front end, sort of like the wheels are out of balance. It only happens when turning the wheel at high speed; when going straight, the car is fine. Any thoughts?

And, is this something I can fix without having to go to a mechanic?

Thanks.