Deeper Targets In Mineralized Ground

[JCR]

There have been numerous threads posted on this subject by experienced detectorists. I always read such posts with great interest as many of my best sites are in some pretty hot red iron ore dirt.  About 15 months ago, in an effort to learn and be more successful, I built a test bed using the same mineralized red dirt I hunt in. This test bed has been very educational and helpful. In addition to learning how each of my detectors perform, and how setting adjustments effect that performance, I have noted something unexpected that stood out that can prove to be useful.  That is the Ground response signal.

 It is well known that at a certain depth, coin size targets start to blend into the ground. The coin goes from a good signal & TID, to an iffy signal & poor TID, to gone. The higher the mineralization the more rapid this happens. The ground has swallowed up the coin.   What I noticed in my testing is that the coin is still detected, it just reports as a ground signal.

 Using the Legend, with Disc A you can hear this response.  On the swallowed coin it is a good, repeatable report with a solid center & good strength. The TID is a solid 1 and the depth meter will fill.  The response from actual ground noise is much weaker and has no center, may or may not give a TID and doesn't show on the depth meter.   Having a good Ground Balance is best but this still shows itself running GB at 0.  TID 1 must be accepted not notched out.

 I suppose this behavior is similar to the old way of hunting in All Metal and listening for the Threshold to null over a deep target, just a mirror image. Perhaps like using reverse discrimination on an early TR detector or running a reverse pattern on something like the Etrac.  Irregardless, it seems to work consistently and well. The Tarsacci MDT 8000, Vista X and Anfibio Multi using the EUD function also will report these types of masked targets but they do it differently than the SMF Legend and not as distinctly.

 The next thing I did was to take advantage of the Legend's adjustability and make a special 6 Tone pattern in Field mode M1.  I set the first Tone Break at 1 & gave it a nice noticeable high tone with decent volume. The second tone bin runs 2-7 with my normal low ferrous tone & volume. The other bins are set for higher targets. This set up may be possible using other detectors also.  Using this pattern, the coin that is swallowed up by the ground gives a good alert & the TID is a solid 1.  You can still monitor the actual ground noise, nails still report as iron and other targets give their respective tones. It works well even on trashy sites.  In my test bed, the Legend will give a good response on targets at 6,8 & even 10 inches using the 6X9.5 LG24 coil which is surprising.  I have only used this special pattern in the field for a few hours. It seems to hold good promise.  I did learn that a deep nail will still give the tell tale double hit down the barrel. Also that less that coin size targets give a noticeable weaker response, so the proportional modulated audio works well.

 There is still more to learn here and time in the field will tell.  I think this has good potential to find deeper coins that are masked by the ground and thought others might be interested and want to try it in their mineralized soils also.

 

[GB_Amateur]

I never detected much in the "old days" so I never learned the tricks you mention.  But seeing this kind of report (along with a few others here) is waking me up.  The new detectors give us shortcuts but it still seems to be the case that "digging deeper" into the "sights and sounds" the detector gives off makes a difference for the deeper (and often older) targets.

As is often the case in every non-trivial endeavor, the ones who put the most effort, time, and thought into the practice have an edge.