One of the main reasons i bit the bullet on the Anfibio, and still have it, is the 9.5 concentric.
This is a huge deal.
An outright dealbreaker.
I have had a number of DD coils, and i dont discriminate between tbem. I hate them all equally. There is one circumstance where i might opt out for a DD coil, and that is highly mineralized ground. However, through much personal experience and testing, ive found that concentric coils almost always have an edge, but especially in iron.
Here's the reason. With a Concentric coil I can set the disc to foil, and a miricle happens; bottlecaps, foil, nails, bent nails, most weird iron blobs, but mostly bottlecaps ALL GET DISCRIMINATED OUT. Sure, a dd may help move some of the crud out of the way and let the user find unmasked targets, but if i wanted to do that with a Concentric, I'd just lower the disc and use it the way its meant to be used, to do what its supposed to do.
But heres the real sticker.
For countries besides the u.s. we have clad coins, composed of mixed ferrous and non/ferrous metals. They sound off and display almost exactly like bottle caps. A concentric coil can diferentiate between the two in sound and on the display screen. The same machine, using a DD coil can not. Vacuming up coins is like taking candy from a baby.. unless you have a dd coil. That guy will be second guessing every mixed metal target in a trashy park. Its really not even so much about leaving trash and finding treasure, as i often just knowingly dig the trash to keep an area clean. What gets under my skin is spending hrs upon hrs learning a machine, and still questioning what the dam thing is trying to say.
I love calling targets before digging them up. Easy peasy with a concentric. If all metals were pure copper, lead, silver, etc, then DD would be fine. That's just not the case.
Now, i started out with numerous tesoros, and ive yet to handle any DD machine that would make me loose my composure in a bed of nails
.
All the old tesoro's, with the exception of the Lobo super traq (which was intended to be used in hot ground), came stock with a concentric coil. It is impressive to see what these machince can do in iron. Im not into splitting hairs, so if the nokta racer or impact does outshine the tesoros, thats perfectly fine by me.
The Anfibio is nice, and speeding up target delay helps. The concentric coil helps too.. but the minute i put the DD coil onto that machine, its whole user intended purpose cbanges, it becomes strictly a water or possibly an easy-digging woodchip machine, but i have lighter units for that. I will not play the secondguessingeverymixedmetaltarget game. No, not on land. Is it a clad coin, a cap, a masked target, a combination of the two, a randomly weird shaped piece of junk, molten junk, or a chain throwing numbers all across the screen? I may occasionally have this issue with a concentric coil, but its so far and few inbetween, that ive learned to understand to some degree what the machine it telling me, or ill dig out of curiosity.
My understanding is that concentric circuitry does not accomodate the multi-frequency platform. I get it. No biggie. I can live with that. Muli frequency has its place.
however, as far as a park and relic machine is concerned, unless its really bad ground, the last coil i want to be using is a DD.
I really wish more machines used the concentric coils today. I feel like besides being great in iron, its practical use is overlooked. Like the new generation of diggers dont know that part (a lot) of the joy in this hobby, is to actually guess and know with some degree of certainly, what is in the ground, before digging it. And with each new DD machine produced, that oneness, that one can experience when really tuned in with their machine, gets to be less and less... kinda like a woman when she constantly leaves you frusterated, all you can think about is ways to get rid of her, lol.