I do mine with sliced meat the marinade is
1 cup Soy sauce
1 cup Brown Sugar
1 tsp cayene pepper
1 TBS Garlic Powder
1 TBS liquid Smoke
soak in marinade overnight and put on rack and dust with coarse ground black pepper then into oven at 200 til dry. I use a dehydrater for jerkey so not sure of time for oven but definatly put a cookie sheet under rack