I've been calling predators for over 40 years now and have never used an electronic caller. Get 3 or 4 good mouth calls and learn how to use them!!
U get much more flexibility from a mouth call. Use a red lens spotlight and have it pointed above their eye level. A 12 ga or even a 20 loaded with 4 buck will kill any yote ever born. Make sure you pattern the gun and load before hunting with it. Predator calling may just be the most fun you can have with your pants on. FRJ