I have planted 'test beds' at many different locations [size=small]
(states, mineralization levels and types of ground make-up)[/size] going back to the latter '60s, and through the years I have seen some improvement on detection depth and target response at varying depths, but I have also noted one other very true realization. That is:
"Very seldom do 'planted' sample targets in recently disturbed ground behave the same as
naturally lost or long-duration targets do in undisturbed ground."
A couple of friends of mine had a detector shop at their home in '68, and I remember planting a number of test targets with him between '74 and '77. I visited the shop location thru the decades since and noted that lawn mowing caused very little build-up of the grass and soil level which meant the buried targets would still be close to the same level as they were planted. Many that were very weak performers initially produced better responses a year or two later after all target and soil conditions were stabilized.
I also noted all during this period that I would find naturally lost coins, trade tokens, buttons, bullets and other smaller-size artifacts at somewhat deeper depths, or at least producing better responses, out in any hunt sites I visited, urban or rural, than I would get from a fresher planted target.
Simple conclusions:
• Lost targets we search for can be located in many different orientations to the search coil than just laying flat in the bottom of a hole where we plant them, and that makes a drastic difference.
• Often the soil matrix, mineralization level, moisture content and compactness are different where we hunt compared to where we might plant.
• We might be hunting a site with a different detector, different settings and/or different search coil than what we used to sample a planted target.
• Planted targets never seem to have the same site environment as hunting in the real world, to include the presence of nearby targets that can cause good-target masking, and even hunting places where EMI can be an issue not comparable to some place we decided to plant a sample target.
Therefore, I only plant things the past decade or two when there is a need during a seminar or demonstration to show the negative effects of some ground mineral conditions that hamper successful in-the-field performance. To ME, the only real and practical 'test bed' is out there. Out wherever we happen to roam and put our coil to the soil and get into some serious hunting. That way we learn the strengths and weaknesses or our detectors, settings and coils, and the site conditions challenges our detectors and coils must handle, and learn and know what we can expect from them. There are countless 'naturally planted' 'test beds' out there awaiting us and they can be much better educators than spending our time planting sample session targets. Just get out and 'test' things out on 'older lost' targets.
Just my opinions,
Monte
