When i do it, I let the butcher do the cuts as normal I ask him to use the trimmings for Hamburger or sausage. When I get it I take what I want to use for jerky and cut it into the strips that I want. I do not use a grinder. I do use my meat slicer to cut the thickness that I want.
I suggest that you test the dehydrator first on somthing like apple slices or even a cut up steak. If it dont work not much wasted. I have one that has 7 trays but thats too many. I only load 4 and I rotate the trays almost every hr.bottom to top. You also have windows to allow moisture to excape. I start these wide open and slowly close them over a 24hr time. If you see steam collecting on the top open it back up. Do this till there is no steam on the top.
Number one thing. Trim ALL fat off the meat. What do I mean? All means all, and thats what all means. Fat will cause the meat do go bad and there is nothing worse than eating bad jerky.
Premix, never use it. I also go very light on any salt item. I use a steak sauce that I order, spices that I like the taste of. I cut the mix with some water and then taste. If its weak I add spices till its the taste I like.
I add the meat to the sauce and let it soak for 24hrs then load it on the trays. I give the meat room to cook, not over laped. Do not add dry spices to the meat, bad news trust me.
If you do a search you will find several different ideas on what to use.
I cook mine till its crisp. Soft leaves room to spoil. Last I place it in a vacume bag and its ready to put in the freezer.
You will find that you try different spices or change someones season mix to fit your taste.
Good luck and let us know how it turns out. Dont skip on time.