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Preliminary Report On New Garrett 11" X 13" Coil For ATX

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I am unfortunately time limited right now, with family stuff occupying quite a bit of time the next couple weeks. However, Garrett was kind enough to rush me a couple of the new 11" x 13" coils to check out and I wanted to give at least a preliminary report on the mono version at this time.

The new coils are aimed at a couple issues that owners of previous ATX coils have complained about. First, the rather unique rear hinge design of the stock ATX coils that allows the detector to fold up into a particularly compact configuration. This design has two issues. As the coils age the forward weight tends to cause the coil to slowly sag forward. Not a huge factor but it can result in constant small adjustments to level the coil out. More important it throws the weight of the coil forward, hurting the center of balance. Again, not a huge issue, but one that becomes more apparent if you try and mow through high grass and weeds with the ATX.

Garrett came up with an ingenious fix for this issue, that both allows the coil to fold up as desired while delivering that center mount coil so many have craved. The new coil design has a sliding channel that lets you move the coil attachment point from rear to center or anywhere in between. You don't see something really new in metal detecting very often but this really is. And it works. Here is a shot of the new coil with the old design inset into the upper right (Click on all photos for large version).



The old stock coil is an epoxy filled 10" x 12" DD design that together with the attached rod assembly weighs 3 lbs 7 oz. The new 11" x 13" mono weighs in at 3 lbs 7.5 oz, again with the attached rod assembly. Basically a wash, although the new coil is slightly larger in overall dimensions. Electronically however it is a much larger coil. A mono coil normally will get better depth than the same size DD coil although in the worst ground DD coils have an edge. DD coils also offer a form of iron discrimination on the ATX that will not work on a mono coil. The ATX seems to be optimized for DD coils and for most gold prospecting the DD coil is probably the better option. For sheer depth on the largest nuggets however mono is often the way to go, and in this case the coil itself is not only a mono but also slightly larger than the stock coil. That is why this coil got my attention first over the 11" x 13" DD version.

I made a quick run out to the northern Nevada goldfields. The weather has finally let up but everything is still real wet out east of Reno. I mean real wet - stick to the bottom of your boots mud kind of wet in places. That oddly helped a bit in this case as the ATX is a PI that can easily handle wet salt ground, and in fact it is my favorite salt water detector. The ground balance range runs well into the salt range so I don't think there is any wet salt ground it can't handle. I should point out however that ground balancing out salt does also balance out small gold signals that read identical to the salt signals. This is one of those unsolvable issues with the way current metal detectors work. But better to tune out the worst of the salt in some places and take what gold can be found still. Listening to constant salt signals masks gold also, so there is no perfect solution.

In any case, the ATX did prove its capability on this little test run as the ground is both wet and salty where I was, and the ATX 11" x 13" mono ground balanced to it with ease, even with the sensitivity cranked all the way up to the highest setting.

Unfortunately I found no gold this day although I did recover some ridiculously small ferrous targets plus some bullets. I did learn a few things to report though. First, the new center mount coils really do balance better and push through grass and weeds much better than the older rear hinge design. The second thing however is more important.

One thing I mention in my earliest ATX reports is that "The stock coil is marginally sensitive to false signals when contacting rocks. This is a bit odd since it is an epoxy filled coil so in theory the coil windings cannot move to produce false signals when bumped. The signals do not occur consistently or often but in my case at least happened most often when the coil would catch a rock on the surface and roll the rock under the coil. It is possible that the coil cable, even though protected by being enclosed in the lower shaft assembly, is jiggling enough to produce the signals."

I never determined exactly what the cause of these false signals were, but others also reported them. They typically occurred only at higher sensitivity settings and could be tamed with careful coil control, but they were an annoyance. The good news is the new coil design appears to have alleviated this problem. I won't go so far as to say completely eliminated yet, as more hours are needed and more reports from other people under other circumstances, but I did not experience any falsing caused by bumping this coil against rocks or other objects. I was getting some faint signals from running a mono coil at max gain riding directly on salt and mineral ground, but that is because I was in all truth running the sensitivity higher than I perhaps should, a habit of mine. I tend to push my detectors hard.

The 11" x 13" mono shares a common mono trait by being hottest around the outside edges. Very small surface targets will tend to signal twice, once for each time an edge passes over the target. This can be handy for knowing you are dealing with tiny surface items before digging a deep hole chasing one. There is also a tendency for the signal to sharpen at the four "corners" of the blunt end coil design. Small targets can be pinpointed by turning the coil on edge and running one of these corners around in the dirt as a sort of pinpointer. When using a plastic scoop to isolate small targets, use those corners as your hot spots.


As I noted earlier I am tied up with family business for a while, but I will be reporting more on this and the DD version in the future. These new coils will have me breaking the ATX out for more prospecting this summer than has been my norm in the past. I have tried the 15" x 20" mono coil for the ATX, and frankly this new mono coil in my opinion is a far better option for prospectors. The rear mounted open 20" length of the larger coil made it difficult to handle in the grassy sagebrush areas I frequent. More importantly, I found that although the 15" x 20" coil does offer more depth on very large targets the gains on normal size nuggets were minimal if any and the smaller stuff can't be detected at all. My honest opinion the main benefits with the 15" x 20" are found both in ground coverage and on very large targets but the lack of sensitivity to smaller gold nuggets is a concern. The 11" x 13" mono is a much better size that in my opinion will offer better depth on the larger nuggets prospectors are likely to find than the 15" x 20" mono coil. However, do not think the 11" x 13" is going to be some kind of huge improvement in depth over the stock coil on large nuggets. People always seem to overestimate the advantages of larger coils. That extra inch? Yes. Twice the depth or even 50% more depth? No, don't set yourself up for those kinds of expectations, they are not realistic.

If I was buying a new Garrett ATX today for gold prospecting, I would be looking hard at these two new coils because the ATX can now come equipped with one of them as the stock coil. The new knock resistant fully enclosed coil design that is also less likely to hang up on sticks and obstructions. The center mount design handles far better. I don't see how any avid ATX user could be unhappy with this new coil design. The DD coil is still probably the better option for most people with the mono more for those chasing the largest nuggets at depth.


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I have edited my original report slightly to repair some fallacious thinking on my part. I had the idea that the new mono coil would automatically be the go to coil compared to the new DD coil or even the old stock DD coil. This thinking is no doubt rooted in my use in the past of Minelab GPX detectors and those models preference for mono coils.

However, anyone that has been around the Minelab detectors a long time will remember that DD coils were the preferred option for many situations on SD and GP models in particular. This is because DD coils have an inherent advantage in bad ground handling capability. A note from Garrett reminded me that the ATX is really designed first and foremost with DD coils in mind, as is reflected in the original stock coil being a modified DD design. The unique ATX iron disc mode also only works with DD coils.

That being the case I have been given a hint that the new DD coil is more likely to work better on bread and butter 10 gram and under gold than the new mono coil. The new mono will likely have the edge on the really big stuff. I will in the future be doing testing to see just how this proves out in reality, but for now did not want my original post to mislead people on the capabilities of the mono versus DD coil. My original post reflected that old mono habit of mine and I have corrected it to be better balanced.

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I sure love how ballanced the atx is with the 8" coil on it. It sure seems to loose alot of depth tho. Of course i usually run mine no higher then 9 on the sensitivity. Mine gets crazy when full throttle! I would love to get the new mono but I can't justify it after buying the 8". 

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  • 3 weeks later...

I would like to see how better the ATX does with his new coils. I was interested in buying a atx after seeing bearkat videos but i also saw what a GPX could do with a NF 17x13 coil. It as sensitive as the ATX while pulling out 1g nuggets at depth deeper than the atx would see a 2g nugget. 

This to me takes away all good things you normally hear good about the ATX like good overall performance in just one setting and working close as good as GPX.



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The ATX is not a GPX and will never be a GPX no matter what coils you put on it. I am very familiar with both and you can read my review here. In general the ATX is better than most people give it credit for, but not as good as other people have pumped it up to be. It used to be the ATX had a clearer place as a much lower cost value proposition. However, with a GPX 4500 now going brand new with three year warranty for only a few hundred dollars more than an ATX with a two year warranty, there is a very clear answer for serious gold prospectors. Get the GPX.

When looking at VLF detectors it is apparent that there are some very good all around machines that can be used for gold prospecting. But in nearly all cases if all you want to do is look for gold nuggets, buying a detector made specifically for that purpose makes more sense.

The same holds true in PI detectors. While they may be used for other things, the Minelab PI series is designed from the ground up for gold prospectors. The ATX has no such lineage and if anything is clearly designed for all around use. From the Garrett ATX website:

Highly Recommended - Prospecting, Cache Hunting, Relic Hunting, Dry Beach/Fresh Water Hunting, and Surf Hunting
Recommended - Jewelry Hunting, Coin Hunting and Ghost Town Hunting

That pretty much says it all. My ATX gets more use as an underwater detector and coin hunting than gold prospecting. And I keep it around for scenarios in prospecting where it shines in dealing with salt flats or certain hot rocks. In the end however the heavy waterproof design and limited coil selection have really held it back from being the machine it could have been for the prospecting community. I look at the ATX as being a superb all around PI detector, but for desert prospecting in particular there are better options in machines made specifically for that purpose.

The new coils are only 11" x 13" versus the stock 10" x 12" size, and some of that may be due to the larger housing. In other words, the coils are basically the same size as the stock coil, and it would be unrealistic to expect a dramatic increase in performance. The mono in milder ground may offer some benefit on multi ounce nuggets, but it will only be on the order of an inch or two at the very most and only on the very largest of nuggets. On most nuggets in most ground you will see little or no difference with the mono, and it does actually suffer a bit as compared to the DD on smaller gold.

These coils, in my opinion, exist mainly to give you enclosed center mount coil options that are less sensitive to false signals from hard knocks. Garrett themselves have made no claims of "more depth" for these coils, and if they were clearly designed to offer on that concept I am sure they would say so. People are reading their own wishes into these things. If you expect these new coils to turn the ATX into something it is not you will be disappointed.

That is not a knock on the ATX. It has been and will continue to be one of my favorite all time detectors. These new coils better suit me for dry land use. I think however both the ATX and Infinium before it were poorly served by people trying to promote it as something they are not, leading to inevitable disappointment for people who acted on those claims. I refuse to be one of those people because I want the ATX to get into the hands of people who will appreciate it and work with it for what it is, as opposed to trying to make it into something it is not.

The fact is due to other commitments I do not expect to be out doing much prospecting until June. I will certainly be reporting more on these coils when I have had time to get sufficient use on them, but hanging around waiting on me is going to require some patience, and I do not expect you will be hearing anything that substantially changes what I have already stated above.

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