Michael,
FYI, unless something has changed that I'm not aware of, electronic calls are illegal here in OK. Wouldn't hurt to give a game warden a call to double-check, though.
Just thought I'd let ya know, I wouldn't want you to get yourself "in a wreck" over that. They CAN however, be used as training aids when not in the field. So if you already have one, you could use it to practice mimicing the sound with a manual call at the house & then be confident that you sound like the real thing once you hit the woods.
Hope this helps.
-Tony