Can't say very much about the larger coil, except I hear they are out there..The 5.75 wide scan coil, assuming that your Tejon is hotter than a Vaquero, will give you 6 to 7 inches on a dime. This is less than the concentric coil gives.. If you are covering a large area, why not consider the 3 by 18 "Clean Sweep" coil. If you set your Tejon up with Disc below nickel,threshold maxed and sensitivity right on ten, do an in air Indian cent and nickel, I can back my numbers off to tell you about what you can expect in mild soil...Sorry I could not answer your question as asked .....