Jump to content

Why No Concentric Coils For The Recent Multifrequency Detectors?


Recommended Posts

Maybe I haven't been paying attention, but with the recent push towards digital multifrequency flagship detectors, why have concentric coils been shunned?  I don't think it's an engineering/physics issue although I can't rule that out.  The White's Vision/V3/V3i/VX3 had concentric coil options and it was digital multifrequency.  Did any of the Minelab BBS, FBS, FBS2 models have compatible concentric coils, either in-house or 3rd party aftermarket?

  • Like 2
Link to comment
Share on other sites


Dilek asked the question on Facebook if people wanted concentric coils for the Legend, so it's obviously capable of running them, she was gauging interest in them and if Nokta should provide them in the future.

  • Like 4
Link to comment
Share on other sites

I could be wrong but the way I understand the differences, at least between DD and concentric design, is that there is better coverage at DEPTH with a knife U shape slice on a DD where the concentric coverage is like a cone with the smaller pointed coverage at DEPTH but better full round coverage on the shallow end.  I like the way concentric has pin-point accuracy and can pick it's way thru some masking targets but in the end (at least for coin shooting) I've preffered the DD for it's coverage advantage in the depth dept.  My question would be...why would a person want a concentric with less coverage on the deep end when every year whatever type target you chase generally gets deeper every year because the easy more shallow stuff has been had??? Never tried concentric on gold nuggs.......

I could very well be wrong so JMO's............

  • Like 1
Link to comment
Share on other sites

I, too prefer Concentric coils in many hunting scenarios. Particularly to better ID Alum trash & reduce falsing from nails.

I always try to purchase them to go with any detector I have. Garrett & Nokta Makro have been especially good at providing them. I hope to see them for the new SMF machines also.

  • Like 4
Link to comment
Share on other sites

1 hour ago, Steve Herschbach said:

Surely most of you see that even with a DD coil your best signal is dead center, and drops off to the tips?

When I get a weaker coin-range signal and do the front-to-back pinpoint method (i.e. moving coil towards and away from my feet) I've noticed that only the center part (about half of the 11" of the ML Equinox round stock DD) responds.

1 hour ago, Steve Herschbach said:

...In general almost all detectors can run both, and users benefit from having both options. But unless people actually buy them, and most will not, then these days I count myself lucky to be able to get a concentric option, and it sometimes drives my choice in detectors as a result.

Glad you responded, Steve.  This is what I was fearing -- low demand leads to low supply.  It took me a long time to appreciate the concentric design, and that was a combination of buying a Fisher F75 3"x6" concentric (from you :wink:) and subsequently using it at Monte's and Oregon Gregg's foray into the Northeast Nevada ghost towns, where iron trash abounds.  I now see why Monte swears by the 5 3/4" concentric for his Tesoros.  I sure hope the N/M Legend has a small concentric coil option.

It's ironic that I once read (either written by Charles Garrett or Dave Johnson) that concentric were easier and cheaper to make.  Yet not even the Eastern European 3rd party aftermarket coil manufacturers seem to want to go that route.  I've been looking at Ebay for a delta (4-pin) 5.75" concentric for my Vaquero.  In the last several months I only remember seeing one and it got snapped up in about a day.  (You snooze, you lose.)  Tesoro and White's were good with concentrics....  First Texas and Garrett, too, in the past anyway.  But it seems that those putting out the modern (fast) multifrequency detectors have no interest in doing so.  Well, unless @Nokta Detectors becomes the exception.  Maybe that's a good way for them to set themselves apart from the competition, in the performance realm, that is.

  • Like 4
Link to comment
Share on other sites

Part of the problem could be the likes of Garrett that include Concentric coils in their entry level machines and market the better DD coil on the next models up. 

The Ace series in particular worked this way, with the Ace 150 and 250 coming with Concetric coils, and a big benefit of getting the Ace 350 was it came with the better DD coil, and their marketing pushed the DD coil as giving the Ace 350 a big advantage.  I distinctly remember this advertising when I was buying my first detector as it is this marketing that influenced me to buy an Ace 350 (Euroace) over the cheaper Ace 250.

Marketing like that makes people think Concentric coils are just for cheap detectors.

You still see a lot of entry level machines with Concentric coils as their primary coil.

Most gold prospectors especially in milder soils are particularly fond of Concentric coils on VLF's.   For some reason I don't understand Concentric coils on the GPZ handle bad ground just as well as the DOD coil, if not better so I think Concentric coils have a healthy future ahead and we may see more of them from Minelab one day too.

When I purchased the Garrett 24k I went to the other end of the earth to get a Concentric coil for it no matter the cost, I ended up buying two to try and get one and I'm glad I did, that coil is my stock coil until Garrett comes out with their own Concentric coil.

As for Nel and the likes, they sell what the market demands, very few people want them and still now manufacturers are always saying DD is best.  I think we'd have more chance of seeing them out of Detech, they seem more open to taking on risks and producing coils others won't with the Arrow a prime example.

  • Like 5
Link to comment
Share on other sites

Gold prospectors are way more in the know. All three coils made for the Gold Bug 2 are concentric, though half the people that own them don’t seem to know it. DD was the way to go on Minelab PI back in the SD and GP days, but since GPX most people favor mono. Not exactly the same thing as concentric, but the principle is the same.

DDs actually suck at small near surface targets. An Equinox plays an actual medley on small surface aluminum, as the complex DD coil field passes over the item and gives varying target id numbers at different places along the journey across the windings. A small concentric is a real pleasure by comparison. I have a White’s DFX not only to run the BigFoot, but also the Eclipse 6” concentric, and the 6” concentric does pretty much stay on the Garrett 24K.

  • Like 8
Link to comment
Share on other sites

16 minutes ago, Steve Herschbach said:

Gold prospectors are way more in the know. All three coils made for the Gold Bug 2 are concentric, though half the people that own them don’t seem to know it.

Those two sentences together sorta struck my funny bone.  I guess it's the half who know those coils are concentric who are *really* in the know.  :biggrin:

Nothing like bad ground and iron trash (around the abandoned camps) to force you into learning to select your equipment and tune your detector or be left with the skunks.  The Western desert ghost town hunters share some of that experience and knowledge.

(A bit OT now, but same principle:)  On one of my Western USA jaunts I was in a New Mexico National Forest campsite on a GPAA claim.  Not only was the campsite itself super trashy but so was the nearby (at that time dry) creekbed because flooding had washed the camp trash into it.  The Eqx w/6" coil was driving me crazy.  After a bit I switched to my backup -- White's TDI PI.  And I never looked back the rest of my time there.  (So it was more than just the trash....)  Driving away I started thinking that a person knowledgeable in setting an IB/VLF for difficult conditions would have done a lot better with the Equinox in that situation than I did.  Always a lot still to learn....

  • Like 5
Link to comment
Share on other sites

  • 1 month later...

Question to the Forum:

Can you miss more targets with a DD than a concentric coil, at the same reachable ground depths (say, 0-5")?

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...