coin garden ans target ID shift question

[dfmike]

I decided to start a coin garden just for the heck of it. I dug a 6 inch hole to put a recent US quarter (looks uncirculated). I made sure the quarter was flat at the bottom. I tested the ID just before I put the coin down and the MX7 gave me a solid 82 in the quarter category of course. Once in the dirt, I ground balanced the detector (60) and I was then getting a repeatable ID but in the dime range (mid to low seventies). Sometimes it would momentarily drop just slightly to the copper penny range. Is a drop in target ID value to be expected when a "new" coin has been recently covered in dirt as opposed to a garden that might have existed for years ?

I'm pretty sure there was no iron present in the soil that could have lowered the value of the quarter. I checked in coin and jewelry mode with rejection volume level just high enough to hear rejected signals but should have checked in all metal I guess. Also, the dirt here is hard packed clay if that can make a difference. Coil used was the stock 950 concentric.

 

[Hombre]

I think you answered your own question with this statement "Is a drop in target ID value to be expected when a "new" coin has been recently covered in dirt as opposed to a garden that might have existed for years?" Yes it is, not only that but the newly buried coin may not give an audio response either.

This is because the ground surrounding the coin is disturbed thus the electromagnetic field is disrupted, much like a loose electrical connection. That is the best way I know how to describe this happening.........My coin garden is over twenty years old and targets act much like those found out in the field. With real world audio and target ID and some have masking iron nearby that I did not take into account when I buried the coins. It took several years for the coins to settle in and report honestly.

 

[dfmike]

Thanks Hombre. I appreciate the help. In the field I would have dug a repeatable dime or copper penny signal anyway. I just didn't expect the ID to drop into another category. Let's wait now and see if it "settles" in a decade or so...