Charles (NY)
02-08-2003, 02:43 PM
I have been attempting to build a double D coil for my Minelab Explorer but I could not get a decent signal on my scope due to EMI in my house. Even using the stock Minelab coil the signal was a mess, looked like a sine wave junked up with a lot of noise.
Then I remembered a discussion with Carl and Erik about how improving the ground on a PI coil had realy cut down the noise so what the heck I connected my scope ground up to the Explorer ground and poof instant, stable, clean square wave!
Hmmm this was with the sens at 10 (1/3 power) so I cranked the sens to 20...it was still rock solid stable. That is normally impossible in my house, the Explorer should have going crazy. Hmmm what about depth...I passed a seated dime over the coil and the depth seemed to be about what I would exepect in the field at sens 20.
I cranked it up to 28 and it finally became instable...but the sens at 20-24 inside my house, thats incredible.
If this glacier in my yard ever melts I'll test this because there is significant EMI all around my house.
Then I remembered a discussion with Carl and Erik about how improving the ground on a PI coil had realy cut down the noise so what the heck I connected my scope ground up to the Explorer ground and poof instant, stable, clean square wave!
Hmmm this was with the sens at 10 (1/3 power) so I cranked the sens to 20...it was still rock solid stable. That is normally impossible in my house, the Explorer should have going crazy. Hmmm what about depth...I passed a seated dime over the coil and the depth seemed to be about what I would exepect in the field at sens 20.
I cranked it up to 28 and it finally became instable...but the sens at 20-24 inside my house, thats incredible.
If this glacier in my yard ever melts I'll test this because there is significant EMI all around my house.