HI , for those of you who want to build a coil for the Garret sea hunter, use this data and wind a smaller coil for in between the rocks on the beach. The inductance may vary from rig to rig generally one or two turns extra will not affect the operation, the impedance is what will affect it, so don't add more than what I have stipulated and have reading outside these values. The inductance is what makes the antenna to spec, work to these figures as it related to the "Q" of the coil, (inductance reactance component of the coil)
I have shown the connection, both coils are wound the placed inside the other one being slightly small to fit inside the other. The TX coil is on the outside and the RCV. coil is on the inside. This is not cast in stone, This unit uses two coils, but yet is classed as a mono coil due to the shape. Coil; testes have been done using 20-30 mA and a small compass to find the coil the direction of winding. Wire size use 18-22 SWG, enameled wire.
Good luck with your experiments, I would post more of the testing but for got to set the camera too a lower resolution it was set on 10 mega pixels, sorry about that. the next task is to get garret plugs, any ideas if one can get these lugs on there own?