Garrett AT Gold Part 2 of 4 (Instructional)

Garrett AT Gold Part 2 of 4  (Instructional)

GROUND BALANCE It’s important to be properly ground balanced when you’re metal detecting, especially when you’re prospecting. A lot of this ground has a lot of high mineralization in it, so as I get into this area I want to be sure that I’m properly ground balance. First, I’m going to do so automatically. I’m simply going to push the Ground Balance button and hold it while I bob the coil up and down an inch or two above the ground and listen to the response. When I’ve got it to a very quiet or near-quiet mode, now I can hunt with stable operation and pick up a good target but not get all the response from the ground. The AT Gold can also be manually ground balanced and if you want to go with that option, you simply press the Ground Balance button and release it until you see the Ground Balance sign come up on the LCD. Then use the Plus or Minus buttons here as you’re bouncing it up and down to run it up until I get rid of that sound. Then run it back down until I just start to pick up a little interference and then just loose it. If I’m happy with that setting, I can click the button again and I’m ready to start hunting. GROUND BALANCE WINDOW ADJUSTMENT The AT Gold’s Ground Balance Window is a powerful feature for overcoming various ground variations, or anomalies. In the average hunting environment, most people will encounter, the Ground Balance Window’s factory default setting of 2 will not need to be changed at all. Now to demonstrate where the Ground Balance Window really comes into play, I’ll go through several demonstrations here in our Garrett test lanes. The Ground Balance Window only applies to the All Metal Mode. So, to change the settings, I use the Ground Balance pushbutton and the Plus or Minus IRON DISC pushbuttons. After you change the Window setting, push the Ground Balance button again to begin operation. Now, this test lane contains highly mineralized soil. You can hear it react. So when I ground balance the AT Gold, I have a reading of 85 on there now. One important thing to note about ground balancing: when you ground balance the detector in mineralized soil like this, it’s very important that you ground balance at the search height at the level you’re going to sweep the coil above the ground. In neutral ground, there’s not much penalty to this. In this hot ground where it’s highly mineralized, I want to balance my coil as close to the ground as possible because that’s where I’ll be sweeping the coil: right above or right on the ground. My reading is 85 when I ground balanced. Now, if I stood here and ground balanced the coil several inches above the ground, I might get a slightly different reading in different terrains. So, in this case it’s always going to get your best results when you get your coil ground balanced at the level where you’re going to sweep it. In this case, I’m getting right down on the ground. And I’ve got a reading of 85 on my ground balance. Now, for this demonstration, we’ve added another pocket of soil here that’s a different color. Both of these soils are very highly mineralized. The difference is the concentration…the level of concentration of the minerals here. But we’ve used a different color soil so it stand out…the variance. Of course, when you’re out in the field, you’re not going to have this luxury. So when the soil is relatively flat and it’s the same color, you’re not going to be able to see when you’ve passed over different pockets of mineralization. But for this test, this will make it easier to determine where the different patch of mineralization, or concentration, is. So, to test these ground anomalies we’ve created here, I’m going to start with a Ground Balance Window setting of zero. So, I’m going to go into my Ground Balance Window and drop it down to zero from the factory default that was two. So, now I’m at zero and I’m running like any other VLF detector that’s in an All Metal Mode right now. Now as I move the coil over these different pockets of mineral concentration, listen to the response. I’ve got the threshold up a little bit so you can hear the audio without the headphones, but you can hear a response from this different pocket of soil concentration. Now, I’ll use the Ground Balance Window and I’ll move my setting to one and go back over this again. I’m only hearing just a very slight response, so if I want to go ahead and move it up to two on my Ground Balance Window and go across it again . . . that’s gone. I’m not picking up any response at all as I go across these two different areas of concentration. So, I’m in highly mineralized ground and I’m effectively hunting with the use of the Ground Balance Window and I haven’t had to touch Sensitivity at all. I’ve got it right where I started out. Now here’s a second demonstration in our mineralized soil lanes here. The contour of the ground in which you’re hunting can actually create variations or anomalies. So, to illustrate this, we’ve dug a little trench here. We’re going over highly mineralized soil in this lane and again we’re in the All Metal Mode. Sharp, uneven changes in the ground’s contour, they can create more pronounced and amplified effects due to how mineralized the soil is. So again, for demonstration purposes, I’m going to have the Ground Balance Window on this machine set at zero. So it makes this detector like any other VLF running in a True All Metal Mode. Now the humps and the divits in the ground, they can create abrupt responses. As the ground falls off when I go over this little trench, you’ll hear a response. So, I’m going to go over this with the Ground Balance Window setting at zero. Notice that response. This anomaly is created due to the suddenly changing distance of the coil to the soil. The more concentrated the soil mineralization, the more pronounced these contour changes can produce such responses. All VLF detectors in a True All Metal Mode are going to be affected by ground anomalies. Detectors with Auto Ground Tracking; they’re still not designed to handle these abrupt changes like this. Even detectors with fast Auto Ground Tracking just don’t keep up with the abrupt anomalies. They’re made to begin shifting as the ground shifts, but it’s not quick enough to keep up with the abrupt changes like this. So to overcome divits and humps in the hot mineralized ground like this, let’s increase the Ground Balance Window. I’m going to start by just going up to one. Right now, we’ve got a strong response. I’m going to go to one and go back over it. You can hear that there’s a little bit of response but it’s already starting to flatten out and it’s already started to calm it down. So, let’s go up to two and listen to it again. It’s much improved, although I’m hearing just a few tails of response. So, in this case, I’ll go ahead and run it up to three on my Ground Balance Window. And now I’ve got a really stable operation, even in this hot mineralized ground. Now, this scenario would come into play where the ground is rapidly changing with cuts, divits, and other anomalies. Moisture is another anomaly that Ground Balance Window can help overcome. The earth is made up of different mixtures of clays and sands and silts and rocks and they can collect different levels of water. Water with any minerals mixed into it is going to be a good conductor of electricity. So there are scenarios where you can use the Ground Balance Window to also overcome those kind of anomalies as well. One important thing to remember about the Ground Balance Window is use just enough. Only use what you need to overcome the situation that you’re facing. It’s the same principle as using too much Iron Discrim. If you use too much or more than you really need, the downside is that your detector can become a little less sensitive to small, faint targets. For a third demonstration, let’s look at the most extreme conditions. And this would be where two really nasty soils of different concentrations come together. So to demonstrate this, again we’re in our test pits here at Garrett. This is highly mineralized soil in this lane and what we’ve got here is one of our gold pans and I’ve filled this up
with some of the most extreme soil that you can encounter. This is Australian ironstone gravel. It’s so mineralized I can literally pick it up with a magnet, like the one on the end of this Retriever tool. This ground will literally stick to the magnet. But I’ve buried this pan of Australian ironstone right in the middle of this mineralized lane to simulate two nasty soil conditions of different concentrations side by side. So, what I’ll do is go back to the AT Gold and turn this on. Of course, it’s going to be at factory settings. So, to make it like any other VLF detector, I’m going to run back to zero on my Ground Balance Window and let me go over the natural soil that’s present here in this lane. Ground balance and it’s coming in at about an 85 here. And what I’m going to do is go over this pan and listen to any response we get from this different concentration of minerals here. There’s a huge response from this Australian ironstone as we go across it. So what I’ll do first is go in here to my Ground Balance Window and I’m going to run it up a couple of points, and check again and see if I have any improved response. Still pretty significant response. You know, again, this is some of the worst stuff that you could every possibly encounter. Uh, I’ll run it up to five and go back over it. Much improved. I’ve still got some little tails of response, though, as I go across it. So, I’m going to go all the way up to six in this case. Now, I’m able to go across it and I’ve got smooth operation going from one pocket of highly mineralized soil to a completely different concentration of really nasty, mineralized soil that’s extremely magnetic. Now what we’ll do is put some targets underneath this and demonstrate the fact that we’re properly ground balanced and we’ve got our Ground Balance Window set to handle this nasty situation. How can we still pick up targets? How is the effect on that? So, let me grab a target here. Alright, here’s a gold nugget. I’m going to take this and actually put it up under this gold pan that we’ve got full of Australian ironstone . . . and put our pan of soil back over it . . . and go over it and listen to our target response. Now, clearly I’m picking up a target there. And that’s after we’ve used the Ground Balance Window setting to overcome these really bad situations. Now, the same thing holds true not just for prospectors but for coin hunters and relic hunters. I’ve got a bronze Roman coin here. I’ll do the same thing. I’ll put it up under this pan of Australian ironstone to simulate a really nasty situation
0:11:35.000 you might find in a place like Italy that has a lot of highly mineralized ground. You’ll need to sometimes overcome similarly really tough situations. So, let’s see if we can pick up this bronze coin. Good, strong response there. So, again the Ground Balance Window is an important tool to come in and overcome some of the worst situations you can hit in mineralized ground. As I mentioned before, the Ground Balance Window has a factory defaul setting of two. That’s going to be perfect for almost any situation for the average hunter. Some of the exceptions might be areas of gold country or places like Australia where the prospecting can be in really difficult, highly mineralized ground with different areas of concentration. Coin and artifact hunters in places like Italy where they have highly mineralized ground, they may encounter some situations like this. And there, by opening up this Window, you’re better able to handle multiple ground challenges simultaneously. And that’s the value of the AT Gold’s Ground Balance Window. THRESHOLD ADJUSTMENT Threshold is the constant background hum that is added to the target response. Use the Plus or Minus Threshold buttons to select from 33 levels. To maximize the ability to hear faint target signals, it is recommended to operate with a faint, yet barely audible threshold. The louder the surrounding environment, the higher you may need to set the threshold. At other times, you might wish to operate with a negative or silent threshold, to reduce detector chatter. Headphones are highly recommended in order to hear faint signals. Garrett Metal Detectos Copyright 2012 Garrett Metal Detectors


  1. These 4 instructional videos are a great help, goes in more depth then the video that came with my detector, thanks for the assistance

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