Concentric Coil For Equinox 800?

[EL NINO77]

When I compared the ALLmetal and Discrimination modes in the 6-inch coil, I pulled the sensitivity up to the level when I feel weak, but regular signal on 13.5 mm -0.54 gram silver Denar coin -is buried at 23cm in the ground ... I got the sensitivity of 14th to Allmetal mode as also at Dyskrimination mode... program Park2, recovery speed 4 ... Signal without ID but clear and regular signal on nonferous metal ...Equinox has very good signal processing...All metall me also definitely outweigh discriminative-better capture signal -If the coil is not exactly above the deep target...like as a mini mix mode...

[Desert Dawg]

I am just not a dd fan. I find a concentric small coil pinpoints much better, and there is added depth over a dd of same size. I can get by with my 6" DD for awhile anyway. Til Steve gets his 6x10 dd.

[Chase Goldman]

1 hour ago, Mxt Sniper said:

I am just not a dd fan. I find a concentric small coil pinpoints much better, and there is added depth over a dd of same size. I can get by with my 6" DD for awhile anyway. Til Steve gets his 6x10 dd.

Yep, those are all the basic DD vs. Concentric arguments for the perpetual coil debate.  I believe, however, a DD overtakes the concentric on detection depth in highly mineralized soil conditions and if you are going after gold, it is more likely than not the soil will be mineralized.  Coin shooting with modern and ferrous trash in mild soil, the concentric usually wins out.

 

https://www.garrett.com/hobbysite/hbby_searchcoil_tech_sheet_en.aspx

[Desert Dawg]

I have used a GB2 for yrs, with the little 3x6 concentric coil, it beats out any dd in that size range. Due to its success ratio no dd was ever built for the GB2.

[Chase Goldman]

3 hours ago, Mxt Sniper said:

I have used a GB2 for yrs, with the little 3x6 concentric coil, it beats out any dd in that size range. Due to its success ratio no dd was ever built for the GB2.

I guess we'll see what ML comes up with. We don't even know if the Equinox is compatible with a concentric/coaxial (elliptical variant) coil much less if it will garner the same performance as on the Gold Bug 2.  My T2 was not compatible with concentric coils at all, that is why I ultimately opted for the F75.  I notice that ML does not offer concentrics for the CTX, E-Trac, or Gold Monster.  The XTERRA has a small 6" concentric but no elliptical coaxial coils, so based on ML's accessory coil track record, seems doubtful they will come out with one (especially looking at the specialized Gold Monster which has not received one to date), unfortunately.

 

2 hours ago, kiwijw said:

This is an interesting thread for me re the DD vs the concentric. With my Minelab PI's & our ground being so insanely mild, mono's were always my favourite coils to use. I love the edge sensitivity of the mono's for gold detecting. Especially the elliptical coils. Knowing the edge is so sensitive you can poke that edge up against rocks, bushes & into cracks & crevices & no gold is save. Not so much the case with a DD where you need to get that DD winding overlap more over the target. So for me the mono's rule. I too love the GB2's little sniper coil & that is the only concentric coil I have on a gold detector that I have given a lot of use to. My Whites MXT I believe is a concentric but I have not used that very much as I have better choices for gold detecting.

So me not being the sharpest tool in the shed, but would I be correct in thinking that a concentric wound coil is closer to edge sensitivity of a mono than a DD.? My reason for thinking this is when I went up a creek with Phrunt (Simon) to help him get his first detected gold with his gold monster by telling him where he should be concentrating waving his coil & why. Letting him go ahead of me & me following behind. I got a signal with my GB2 that certainly pulled me up. So I called Simon back to wave his 5" DD coil over it. He said he had poked his coil in there & got nothing. Really, I said. Listen to this.....He heard it & tried his again. Nothing. So I hacked away at the schist & the signal was still there but Simon couldn't get a peep out of it. He thought I was chasing a ghost so he buggered off & continued further up. It turned out to be a 1.5 gram flat, squashed but chunky bit of gold down on edge into the schist bedrock. My point being that Simons 5" DD coil on the gold monster didnt get the signal waving it flat over the bedrock & it is quite a bit fatter, on edge, than that lovely little sniper coil on the GB2 & he couldn't get it on edge down into the crevice as far as I could the GB2's. End result being he missed getting that signal & I believe it was due to the lack of close to edge sensitivity on the DD coil.

What I don't recall now, is that when I first got that signal that pulled me up, was it from waving that GB2 coil flat over the bedrock....or did I poke the edge of the coil down into the crevice???? Which I was able to poke a bit further than the little fatty GM DD coil. The 5" DD at 45 khz should get better depth than the GB2's 71. So waving the coil flat over that bedrock I would have thought the 5" round DD would have got the depth. Even more so when it is 5" & the GB2's is 3.5" wide. Is there something there in the difference between concentric vs DD??

I know this thread was about concentric for the Nox, so sorry for deviating, but interested in the concentric vs DD debate. for me...more for gold prospecting than coin & relic. Cheers.

Good luck out there

JW 

The mono coil edge sensitivity appears to exist due to the fact that a mono coil has either a separate transmit and receive windings in close proximity around the circumference of the coil or a single transmit and receive winding is used.  Concentric/coaxial coils have the transmit and receive windings spaced further apart with the receive winding being the smaller diameter inner coil.  So edge sensitivity is less likely with a concentric and it has better pinpointing ability and depth penetration in the absence of mineralization.  Edge sensitivity can and does exist on the receive winding half of a DD coil.  These are general facts for the different coils.  Can't comment on the specifics of your situation because I am unfamiliar the coils and detectors in question.

[D&P-OR]

13 hours ago, Steve Herschbach said:

Well, first we need to get the 12" x 15" DD out the door. And then I want my 6" x 10" DD coil. Then maybe we can start talking concentrics! 

Right!!!!!!!!

[Chase Goldman]

3 hours ago, phrunt said:

The most unusual thing is my Minelab Go-Find 40 has a 10" monoloop coil and it's a VLF.

Yeah.  I was wondering the same thing as monos are typically only seen on PI's.  Really technically curious why ML went there besides cost and the performance compromise  vs. a DD or conventional concentric/coaxial.  Also wonder if it isn't a dual wound monoloop (i.e., essentially a coaxial with both TX and Rx coils separate but co-located at the perimeter of the square loop).

[Desert Dawg]

I am sure you all have seen the Whites double Coil package that comes with the new 24K, a dd elliptical and a concentric. If whites can do it, I am sure minelab could if they desired. There is a lot more than meets the eye about the properties of a concentric on a VLF.

Edge sensitivity being number one to me, also spot on pinpointing unlike the long thin coils overlap line of a dd. The first thing my hunting buddies wanted to know about my new detector, does the 6" coil have edge sensitivity,  I had to say no. 

[Chase Goldman]

1 hour ago, Mxt Sniper said:

I am sure you all have seen the Whites double Coil package that comes with the new 24K, a dd elliptical and a concentric. If whites can do it, I am sure minelab could if they desired. There is a lot more than meets the eye about the properties of a concentric on a VLF.

I have no doubts that ML has the technical ability to deliver a concentric (provided the Equinox is compatible, which is an unknown). All I am saying is that their track record especially on their latest detectors including a dedicated gold machine, indicates that they will not bother doing so.

Whites is pretty consistent about offering both DDs and Concentrics as accessory or stock coil options for practically all their machines.  Would be nice if competion from Whites on the 24K spurred ML to do the same, but so far there is no indication ML feels threatened by the new machine. Hope ML surprises us with a new coil announcement.