FT16000 search coil

[Stevedbk]

I have a FT16000. Recently the coil was stepped on and fractured the plastic on the top section so I took the opportunity to have a look inside.
The format is DD, one coil is Litz 1mH, 4.4 Ohms. The other is enameled 13 mH, 176 Ohms. There is a loop of several turns approx 20mm on the enameled wire which I assume to be for nulling.
The diameter of the form is 195 mm, 17mm thick.
Both the top and bottom have a painted conductive shield on thick paper which do not overlap the edges of the form. There is a single wire
joining them. The resistance at 1cm is 40 Ohms, edge to edge 100.

Steve

[Carl-NC]

Here is what I recall to be a Sovereign coil. Obviously the exact same foam holder, but in the Sov there is a preamp PCB in the square recess. I've always assumed in this coil that the TX coil is on the left and RX on the right, for 2 reasons. First, you normally bring the cable in on the TX side to minimize dynamic coupling to the RX coil. Same with an internal PCB, you want it on the TX side. Second, there is a small pick-up coil under the tape (NW corner of the PCB) which couples to the TX field and generates the power supply for the PCB. That coil should be inside the TX coil for best coupling. After looking at your coil I should take a closer look at mine.

[Stevedbk]

That's interesting information.
Thanks
Steve

[tony_av]

I dont now if this image is an original coil. There is a small coil witch is nulling coil. The power supply is taken from TX coil.