You do not necessarily need a food dehydrator to dry food. A convection oven works well as a food dehydrator because its fan and convection cycle speed up the food drying process. Drying food in this way prevents the formation of bacteria, yeast and molds by removing the moisture from the food. It also slows the enzymes that will eventually break down the components of the food.
Heat your convection oven to between 140 to 160 degrees Fahrenheit.
Place the food to be dried on a cookie sheet so that the food edges are not touching and there is plenty of air circulation around the food.
Put the loaded cookie sheet into the convection oven.
Close the oven door or experiment with propping it open with a wood spoon for more air circulation.
Remove a piece of dried food from the convection oven, and let it cool before you taste it to determine its level of dryness.