Freeze turkey until firm but not hard; then cut into 1/8- to 1/4-inch-thick slices.
In a medium-size glass, stoneware, plastic or stainless steel bowl, combine onion powder, garlic powder, water, soy sauce, Worcestershire, sugar, pepper, and liquid smoke. Stir to dissolve seasonings. Add turkey and mix until all surfaces are thoroughly coated. Cover tightly and refrigerate for at least 6 hours or until next day, stirring occasionally; recover tightly after stirring.
Drying the jerky: Depending on the drying method you're using, evenly coat dehydrator racks or metal racks with cooking spray; if oven drying, place racks over rimmed baking pans. Lift turkey from bowl, shaking off any excess liquid. Arrange strips close together, but not overlapping, on racks.
Dehydrator drying: Arrange trays according to manufacturer's directions and dry at 140 degrees F until a piece of jerky cracks and breaks when bent (4-1/2 to 6 hours; let jerky cool for 5 minutes before testing). Oven drying: Set oven to 140 to 200 degrees F (the lower, the better-- the lowest your oven allows). Place racks at least 4 inches away from (above or below) heat source. Prop oven door open by about 2 inches. Dry until a piece of jerky cracks and breaks when bent (4 to 6 hours; let jerky cool for 5 minutes before testing).
Pat off any beads of oil from jerky. Let jerky cool completely on racks; remove from racks, place in a rigid freezer container, and freeze for 72 hours. Then store in airtight, insectproof containers in a cool, dry place; or freeze or refrigerate.