Running The 15" Cc X Coil Over A 6000 Patch

[GotAU?]

10 hours ago, Aureous said:

The term comes from the first 2 syllables Con-Cen-tric. CC.....as in the better lookin Cousin of DD 

How many people searched “CC coil” to figure out what it meant? 🙄

(insert paper bag on head emoji here)

I am finding that I really like the DD though, not only just for its EMI handling, but also for its double sided response to shallow targets- that’s pretty useful for locating them.

[jasong]

Targets on the 6000 seem to go from "not there" to "good target" fairly quickly on the 6000. Wheras the 7000 seems to have much more nuance with the faint signals, they increase in intensity slower, not all at once like the 6000 likes to do.  This quirk can be useful since it's much quicker to chase and dig the signals above the intercept point with the 6000, and much quicker to chase the fainter, more nuanced once with the 7000 below the intercept point. At least, IMO.

It's like the 6000 has an exponential target response and the 7000 is more linear. At something like this is how it feels in my head:

[phrunt]

That's what I've been trying to describe, you've done it better than I did 🙂

 

[jasong]

Got out for a bit of exploration on the ATV and 6000 again. More scatter shot prospecting, trying to expand gold bearing zones. Covered a ton of new ground. Unfortunately nothing new turned up. 

I also brought the skunk buster with me (GPZ + 15" concentric X Coil) so I could end the day with something in my pocket if exploration failed to produce, and decided to run the rest of the sun down by hitting some deep gold bearing ground for a few hours. The 6000 had given no gold in this deeper ground, other than a few nuggets I recovered towards the spot where bedrock started poking out of the dirt towards the periphery.

Within a few minutes I hit a small one. It was about 4" deep and I could actually still see my old footprints where I had run the 6000 over this very spot. Quite a loud target on the 15" CC and another one of those targets that left me scratching my head how the 6000 missed it. I was very careful to remove layer by layer so I could know exactly where the nugget was in the hole, it ended up being at the top of the scoop almost under the rock.

Keep in mind, this 15"CC X Coil is IMO outperforming the 17" spiral X Coil, which itself is outperforming the ZSearch, which itself is outperforming the stock 14x13 GPZ coil. So it's not like I'm running anything even remotely close to the stock the GPZ here, and if a reader is running stock, they shouldn't expect the same large differences I am seeing. But still, the amount of missed targets I've been finding that seem like they should have been found with the 6000 is pretty exceptional IMO. 

I worked closer to the edge of the bedrock, but still in the deeper dirt, with my old footprints still visible in a grid. And about 10 minutes later I hit another target, this one virtually screaming. Again I picked down layer by layer with my fingers until I saw the glint of gold so I could see exactly where the nugget was at in the hole. This one was probably 6-7" deep, in some roots. It ended up weighing something around 0.45 grams.

A bit more work around the bedrock periphery and I hit on 5 more little nuggets, almost all in the grass roots. I was intentionally ignoring the salt signals (of which there were many), also rejecting any faint or somewhat questionable signals. I was concentrating only on the obvious, strong target signals, of which there seemed to be plenty.

It's pretty clear to me now that the 6000 is missing a lot of stuff in this size range below about 5", something good to know so I understand when and where to use the 6000 and how to interpret my results with it. 

I began the walk back to my ATV, doing a quick swing over some of the ground with no bedrock exposed. I had one final strong signal, this one was down probably 9-10", at the tip of the scoop. It ended up being the heaviest of the day at a whopping 0.57 grams, a bit thicker than the others.

So, 8 nuggets (on the left, low light makes the contrast bad) for the short session and 4 bits of trash. All the trash was also 4" or below, the 6000 got all the pellets here. The smallest nugget 0.12 grams and the largest was 0.57 grams. I am in an area where the gold rarely gets above 1 gram.

I tried a bit of prospecting, working a little new area on the way back that I had found 1 straggler nugget with the 6000, but it was totally infeasible due to salt. 

Maybe easy to understand why I was earlier so concerned with determining if larger or concentric coils can be made for the 6000 to give it a little performance boost. I wasn't rabble rousing, it was a serious question that needed an answer. Seeing results like this instantly makes me wonder what a 12" lightweight concentric on the 6000 could have done as far as cutting into missed nuggets goes, while staying light weight.

But, seems that is not possible for whatever reasons on the 6000. So, good to know now. And I can only hope that coil manufacturers offer concentric options in the future for detector models that are compatible with them. I'm left curious if CC's offer as much depth gain on PI's, or if they outperform on ZVT tech only, relatively speaking. 

[Norvic]

Yeah Concentric coil back in the 80s I had on my Garret A2B was the same as on the Z, extreme depth ( for VLF now ZVT) with lessened coverage, as per my post back over a year ago. You`d reckon should be a possibility for the 6K, come on X coil.

X coil as stated before your welcome to my 14inch, to have a go. My 6Ks well and truly paid for ready to try.

In regard to the 6K, although it has top audio response over other detectors on those shallow scraps tis those subtle but repeatable "ghost" signals that produce the weight.

[jasong]

These are the first concentrics I've used on any detector, so I'm just basically learning about them. 

I'm curious why they were never very common on the GPX/GP/SD's? A VLF has some ZVT like qualities, are they less effective with true PI detectors? 

[Norvic]

To my knowledge there was only one company making concentric coils for the VLF gold machine that was Dtek (spelling from memory) they also made the Search King 15Khz and the Gold King 5Khz VLFs in direct competition with Garret. They did not catch on, along with the concentric coil was shunned in my part of the world for a reason I didn`t understand, got the weight for me.  

[phrunt]

On the GPZ the concentric coils have an outer transmit and two inner receive windings, and to top it off they're flat wound.  I can imagine the inner most receive winding is very small which might explain the super sensitivity they have.

Also that outer transmit winding on a 15" CC is a big winding, if you think about the standard DOD design.

 

The central transmit winding on the 14x13" GPZ coil is tiny compared to the transmit on the 15" CC.  I have no idea myself but you'd think that might have something to do with why the Concentric coils are so deep.  Just a guess of course, I do not know why they're so much better.

[Aureous]

13 hours ago, Norvic said:

To my knowledge there was only one company making concentric coils for the VLF gold machine that was Dtek (spelling from memory) they also made the Search King 15Khz and the Gold King 5Khz VLFs in direct competition with Garret. They did not catch on, along with the concentric coil was shunned in my part of the world for a reason I didn`t understand, got the weight for me.  

Concentric coils were quite common with many company's back in the 80's, along with Co-planar and coaxial designs. The company you were referring to was Detex. Yes, very Garret-like and I think Garret bought out the company. Whites were big with concentric coils too.

[jasong]

7 hours ago, phrunt said:

On the GPZ the concentric coils have an outer transmit and two inner receive windings, and to top it off they're flat wound.  I can imagine the inner most receive winding is very small which might explain the super sensitivity they have.

Also that outer transmit winding on a 15" CC is a big winding, if you think about the standard DOD design.

The central transmit winding on the 14x13" GPZ coil is tiny compared to the transmit on the 15" CC.  I have no idea myself but you'd think that might have something to do with why the Concentric coils are so deep.  Just a guess of course, I do not know why they're so much better.

So due to these factors, we should probably expect a bigger performance gain from concentric coils on machines that use these DOD coils stock than we would expect to see on traditional PIs using monos which already have a large RX/TX loop?