Author and two box detector.
Special detector designed to reach large metal objects in great depths. Ignores small pieces of metal.
After this second day I did not return to this place with one exception several months later. The manufacturer of my metal detector offers a very large coil called the depth multiplier which allows to find large targets very deep. This design is also called two-box detector. I returned to the site with this accessory and re-searched the same area but no more relics turned up.
Nevertheless, relics were found and an unsearched skirmish site was discovered. An old painting turned out to be a faithful witness and I really enjoyed this historical detective story. Hope you did too!
Bye, and happy hunting,
(C) Thorsten Straub www.metal-detecting.de 2006-2011.