Metal Detecting in the "Large Cents" Land Again
Unfortunately, Alexander had only a standard 10.5" search coil with him, so detecting around the cellar in All Metal Mode was out of question for him. The coil of large diameter would cover a few targets at the same time, the iron junk targets would certainly mask the good targets. Alexander set up Discrimination on Coins/Jewelry. But I knew that he would face a problem with false signals anyway due to the zillions of square nails in the ground.
These Nail Fragments Would Easily Challenge a Minelab Operator
As for my detector, it was not my old and good Explorer II this time. I left it in Europe. Now I was going to use my Tesoro Cortes which had proved to be a better machine for searching the cellar hole sites.
After having used the Minelab Explorers for past six years, it was weird to me not to have Tone ID or automatic ground balance. I could not remember when I did the ground balance manually last time! Well, I had to do it now. While I was struggling with that, Alexander was digging up something.
Finally I tuned my Tesoro and set up Discrimination on just a bit above the iron mark. The great thing about Tesoro is that it "loves" iron and allows the operator to hunt in All Metal Mode without being annoyed with cacophony of false signals. With Cortes, I could easily determine if a square nail was small or large.
Not to miss a good target that would be in close proximity to the iron junk, I decided to search in All Metal Mode and switch to Discrimination mode every time I would encounter a non-iron target. The only inconvenience was that I had to read the target's information on the screen every time I would get a signal.
Tesoro Cortes in Action
I decided to search the area around the cellar hole first. I mentally drew a circle with the radius of 10 feet and the cellar hole positioned in its center. I divided the circle in four quadrants and began searching one of them in a crisscross pattern.
Right away, I started receiving lots of iron signals from square nails and their fragments. Occasionally, I dug up a larger piece - a fragment of iron cookware or a door hinge.
Only when I moved into the second quadrant, I received the first non-iron signal at the spot where Alexander was digging before. The target turned out to be a brass thimble.
I called my buddy over to show him my find and tell him that it was important to recheck the hole for possibly more signals. Most likely, the thimble was partially masked by the large square nail which the Minelab Explorer would read as a high conductivity target due to the nail's strong "halo effect." Alexander dug up the nail but left the thimble in the hole.