EMI question

Hi Adrian,

The gpx detectors sample early enough to see the magnetic field that was built up in the ferrite, still collapsing. On most other pi detectors the first sample is taken in ample time for the ferrite not to be seen.

The Z is very(mostly kind of)different. It is always on, just alternating its magnetic polarity, so once again there is going to be a lag in the polarity change in the ferrite which will be seen/detected to some extent.

Noyungan, yes you are right, in general you want to balance on the "common" ground.
However, in places where there are many hotspots, quite often these hotspots all share the same characteristics. What you can do here is mark the hotspots as you find them, then balance on one and go back and check the rest. Most likely if one of those hotspots is a valid target, it will sound off, whereas the rest will mostly have been cancelled out. The ground in between the hotspots will now be noisy.

Also when you are digging a suspected target, always keep checking the dirt you have removed and if you are getting a response from it and still in your hole, balance to the dirt on your heap and recheck the hole. If suddelny the noise from the hole is greatly reduced/gone and there is no particular spot in your heap, you can fill it back in and get on your way.

Cheers Mick

Hi Mick.
Thanks for that little bit of techo info.