Swapping Coils

I don't think your machine will recognize a coil from another manufacturer, unless it is made to the specifications of your particular machine. NEL makes coils for Minelab machines, but it's not a universal design - it's model specific.

I wouldn't even bother trying since your ML will reject it as unidentifiable...and I guess could hurt the motherboard in the CPU, not worth the risk if you already know it won't work.

Yeah as Ollievon said I doubt the machine would even pick it up. Other companies will make coils for a detector (for example NEL and Coiltek make coils for the Minelab X-Terra series), however coils from companies such as NuggetFinder, Detech, Sunray, Teknetics, Garrett, Cors etc etc might not (and will probably not) work on the xterra.

Same goes for other detector models etc. You probably couldn't use an AT pro with an 11in Minelab coil for the CTX.

Not only are coils made for a specific model machine some of them are also run by the software in the machine. Coils that are made for a specific machine will not work with a different model from the same manufacturer Let alone a machine from a different manufacturer.