I covered that in my response when I said it works on deep coins too. Dug a merc dime 6" down and pinpointed it the exact same way as G4E in his video. Cut the plug at the end, and it was exactly where I thought it would be. I'm not saying your wrong, I'm just saying that my experience has been the same no matter how deep the coin is, so how does a DD sound off on the edge of the coil on a deep coin if it is detecting a cone shape?
You have made it clear you don't like the DD, but I'm telling you, nothing you have said matches what I have seen in the field. You say you have tested many of these coils and I have only had one for 2 months, so I'm not claiming to know what I'm talking about, but I bought the coil for greater depth and because my research showed it detecting in a U shape along the narrow band in the center of the coil. When I bought it, and tested it, it appeared to do what It claimed to do. Now I don't know, so I'll have to try it with your thoughts in mind.
Hi. A DD doesn't sound off on a coin at depth , at either the tip or the rear, on the edge of the coil.
Sometime a plug may give an impression that it has held a 6 or 7" coin, and has allowed you to slide along its path to near the tip, when in fact the coin was only an inch to two from the surface and well within a DD's cone.
You may have misunderstood somewhere along the way and you seem to think that I've made it clear that I do not like DD's. The opposite is true.
I was merely trying to help people understand how a DD works.
Ten years ago you couldn't get an American coin hunter to even try one. Now every wants one because they are sucked in to believing that you get more "coverage with a DD.
They had a bad name for many years, and that was due to the poor quality of the units that were manufactured that were using them. The detectors themselves could not handle mineralized ground, so if a user put on a DD and realized the slight depth loss, worked out that a badly made DD gave them no more advantage, they'd go back to a concentric.
And I guess the point I'm trying to make there, is that some manufacturers make very poor concentrics, DD's, and units. It might surprise some people to learn than some concentric move very nicely through heavily mineralized ground, depends on the brand , year, coil and unit. Some DD's are very insensitive ie : tesoro widescans. A lot of people are misled into detecting myths.