Building My Own Coil!

[phrunt]

I believe the detector would need to be capable of running the bigfoot design, you would be limited to making a DD coil like the Detech arrow to run on everyday detectors.

[Steve Herschbach]

19 hours ago, phrunt said:

I believe the detector would need to be capable of running the bigfoot design, you would be limited to making a DD coil like the Detech arrow to run on everyday detectors.

You can get a figure 8 winding to run on any detector. The problem with most is that you will have a reverse polarity front to rear - the tones will literally flip with the winding. You see it in various Bigfoot coils made for the XLT and MXT and other machines. Even with PI detectors running the old Coiltek Salt Compensation coils, which were simply figure 8 windings. Not only great on salt but very near immune to EMI and renamed later to reflect that. The White's DFX was unique in that it was built with Bigfoot in mind and so had built in compensation for the polarity change. An advanced coil builder could probably put a chip in the coil that would do the adjustment in the coil instead of in the detector.

The problem is making a VLF figure 8 is a touchy procedure and DeTech went DD just because it is easy to make them.

[SwampFox]

47 minutes ago, Steve Herschbach said:

You can get a figure 8 winding to run on any detector. The problem with most is that you will have a reverse polarity front to rear - the tones will literally flip with the winding. You see it in various Bigfoot coils made for the XLT and MXT and other machines. Even with PI detectors running the old Coiltek Salt Compensation coils, which were simply figure 8 windings. Not only great on salt but very near immune to EMI and renamed later to reflect that. The White's DFX was unique in that it was built with Bigfoot in mind and so had built in compensation for the polarity change. An advanced coil builder could probably put a chip in the coil that would do the adjustment in the coil instead of in the detector.

The problem is making a VLF figure 8 is a touchy procedure and DeTech went DD just because it is easy to make them.

Thank you Steve, I in fact own and use 2 DFX's as well as a Spectrum Eagle. I have as of lately been on a much simpler mission in building Lithium-Ion battery packs for several Whites and a couple of MineLab metal detectors. For years I have always used Alkaline Batteries in a standard battery pack instead of using rechargeable batteries. The reason being is Ni-Cad and Ni-Mhd batteries start to loose voltage the second you start to use them so I used Alkalines because they are much more stable voltage wise. Only recently have the Li-On batteries come to a point in their development that the Voltage is super stable until the current is depleted somewhere in the 75th percentile. But back to the coils I am first working with the Whites DFX as well as a couple of MineLab detectors I have already built a couple of DD coils. I am experimenting with the angle plane of the coils to see if I can enhance in any way significantly, the functionality of the detector. I am basing my work  on the fact that Magnetic Loop Antennas can null out interference by being off peak to the hottest point of a received signal. I know the Transmitted signal should be coupled as best as possible, however in my experience often a weak almost unreadable signal may be detected by rotating the Receive Loop off to one side or the other from maximum coupling. I work with a guy a few years ago who used various ferrite cores, some loop others bar shaped to cause the magnetic pattern to be shaped into an extended or oblongated pattern. Anyway thank you for your previous information in your earlier post. Laurin

[rvpopeye]

Interesting stuff ! I'll be following your efforts.🖖

[bklein]

I was focusing on a Bigfoot for a PI detector. Worked great on a GP extreme. Maybe all the gotchas are only true with a vlf?