Using The 7000 To Pick Up The Scraps Missed By The 6000

[dig4gold]

45 minutes ago, phrunt said:

The 8" coil is my favourite of the smaller coils, being the smallest, more of a specialty coil as you're not going to cover ground with it, but it's ideal in this situation you're in there and I would not be at all surprised if it picked out gold you're currently missing with both combinations.  A compromise is the 10" as it gets a more normal ground coverage with just a little less sensitivity which of course means a little less depth on the smallest bits but a bit more depth on bigger bits but even coils like the 15" Concentric are very competitive with the 8" on small gold, only falling slightly behind more similar to the 10" while providing plenty of other benefits and would be my overall pick of coils.

If only Minelab made more coils for the 7000, or at least sanctioned other brands to do so to make them more mainstream I think these 6000/7000 comparisons where people favour the 6000 by a large degree on smaller gold would largely disappear.

That 8" would be the Russian made X coil which needs the adapter to run on the 7000.

D4G

[Lesgold]

Your comment about the six going from no signal to a screamer in a short distance is so true. My mate and I were out detecting yesterday and I had this situation arise twice. I went to a shallow rock bar that had produced a few small pieces on previous trips. I decided to move some rocks so that I could get the coil a bit closer to the bedrock. Initially I checked a small area for any evidence of a signal and then a thin piece of shale type material was removed. When the shallow water cleared, I could see the bedrock below and ran the coil through that area. The six screamed. After a bit of fluffing about, a small nugget was retrieved. In another situation, I ran the 10x5 coil over some damp bedrock that had a thin layer of clay sitting on it. It was potentially a good area to trap a piece of gold. When I ran the coil over the clay, the machine didn’t have a break in the threshold but gave that sort of low pitched moan type sound that tells you there is something there that it needed to react to. It was very much like the sound you get when you run over some mildly mineralised ground. As it was in one confined area, a scrape with the pick was in order. About half an inch of clay was removed and the area was detected again. The machine reacted in protest. Again, a small piece of gold ended up in the rattle jar. When working mullock heaps that contain gold, removing material an inch at a time before detecting often pays dividends. This issue is more evident with the smaller coils (which is to be expected). There was a comment earlier about running in normal. It is fantastic if you can and does produce outstanding results. In the area that we are currently working you could run both machines in normal if you wanted to. The only issue would be that running in normal would reduce the life of the detectors…………. Within ten minutes they would be wrapped around a tree and have huge rocks dropped on them from a huge height. 

[phrunt]

This is from the CTX 3030 manual.

Volume Gain Range: 1–30 Factory Preset: 24 Volume Gain controls the amplification of a target’s audio response, relative to the target signal strength. This audio setting is most similar to volume adjustments in other devices (e.g. radio or television volume controls). With a setting of 1 the target signal will not be amplified. Weak target signals will sound quiet, medium target signals will sound mid-range and strong target signals will sound loud. There will be greater differentiation between target signal strengths; however, weak signals will be harder to hear. With a setting of 30, all target signals will be amplified to a loud audio response. At this setting there will be less differentiation between medium and strong signals, but weak target signals will be easier to hear

I've put into bold what I think the GPX 6000 has incorporated into its audio, as targets can go from scream to nothing with the smallest amount of depth, especially small targets like pellets and small gold.  I believe this is part of what makes people think the 6000 is a magical detector on small gold, by having the faint target signals boosted it appears to be much more powerful on smaller gold than it in fact is which is evident by how quickly the signal falls off.

Yes, it's a very good detector on small gold, but some of it is trickery done with software.

You just need to use a coil like the 8" on the GPZ and then use the 6000 with the 10x5" coil and experience a number of smaller targets like pellets and gold and you would start to see what I'm saying is very likely correct with the differences in audio responses vs target depth between the two.  There is a reason the 6000 goes from a screamer to barely a target at all on a small pellet with only a cm or two of depth difference, in fact a lot of people were confused and talking about disappearing targets with the 6000 recovering these tiny bits, I wonder why that could be? they don't need to move far to go out of range so flattening out the pile is the way to go.  Confusing a loud screamer like that can just disappear.... yet when you understand how the audio works it makes more sense.

I use the CTX a lot on this "30" setting, so the behaviour was very familiar to me when I started using the GPX.

[Lesgold]

Thanks Phrunt. That sounds just right for the 6000. Just about to head out now with the detector to see what turns up in that patch. 

[dig4gold]

It is crazy too how when the signal is in the scoop, with what appears to be a small amount of earth material, the signal can go from faint to a screamer as you remove material & whittle it down as you wave the scoop over the coil.

D4G

[phrunt]

When you think about it, it's a highly effective way to make a detector stand out as being sensitive to very small gold, when that audio signal on small targets is boosted right up.  It's not necessarily hitting them any better than it would if it had the more traditional proportional audio, however they stand out a lot more, so people harder at hearing, or less inclined to notice faint signals are never going to miss them when they're amplified like that.  It's I believe a big part of the magic that has made the 6000 so successful on smaller gold for a bulk of people as it's just easier for them to find it.   It's a nightmare for shallow pellets though, and I much prefer the GPZ for that, the double blip, and the normal depth indicating audio.

You certainly don't need to focus as much when the detector is doing the work for you.   It still does weaken off on the signal as they're very close to out of range, as does the CTX with it's targets, but it doesn't do it in steps as much as a normal audio detector.   A very successful idea to use this type of audio on a gold prospecting detector, as it's just what you need when the focus is smaller gold and the idea behind the detector according to their marketing was a detector that made you an "easy expert, you'll be an expert from the moment you turn it on, Finding gold has never been easier".   And aside from its rough threshold, they're right.

[Lesgold]

Couldn’t agree more Phrunt. It has made life easy. I took my eldest daughter and grandson back to this spot with the 6 in tow. I knew that there would be gold left in that patch but gee, it was small. It was my grandsons first real attempt at prospecting and he picked it up quite well and had a ball. Just cleaning up the “fly specs” now. Just for a bit of fun I took two pans of the gravel and panned it out. Had to walk about 40m to get to water so it lost its appeal quite quickly. Here’s the result. I was quite impressed. If I was keen, I could classify a few buckets and have a play in the water. The problem with doing that is detecting time would suffer. So maybe not just yet. Lol.

[Lesgold]

Cleaned up the gold that the 6000 recovered. What you see is actually the result of a lot of careful work so in reality the 7000 actually did quite a good job. When we arrived at the patch, I had my 12 year old grandson run over the ground before any gravel was disturbed. He found 5 targets that were obvious which was pretty good as he had never been detecting before. We dug those pieces (which were very small) and then systematically turned over the ground and dug a little deeper and wider to recover the remaining pieces. As soon as we hit hard packed, dirty gravel the gold disappeared which indicated that it was a drop zone during floods that occurred late last year. I’m sure that the Zed would have squawked on some of those larger pieces if we had followed the same detailed search procedure a few days ago. What Phrunt has been saying was really reinforced and made obvious as I watched my grandson and daughter searching this area. I spent most of the day watching and filming as they enjoyed the excitement of the hunt. Often a scrape of an inch would reveal a screaming signal that was not audible a minute earlier. Gold signals lost in tailings piles or a scoop that had too much material in it were a common occurrence. To his credit, my grandson soon leant the tricks required to achieve success. 

The gold in the photo weighs just over a gram. The pieces that were panned were dried and weighed and came in at just over .2 grams which was surprising. There may have to be a rethink about leaving the remaining specs for someone else.

[Lesgold]

Simon, I have a question or two for you in relation to the 8” Xcoil. How does it perform in relation to the 10x5 Coiltek on the six? I assume it would have pretty good sensitivity but what about depth? It could be another option in my situation as I have family members who would grab the six every time and leave me twiddling my thumbs. I have heard a mate say that it was very good up at Tibooburra on the small stuff but this was only hear say. I assume that it would love hot rocks even more than the. Six. I know why they are called Xcoils. The “x” is for expensive (especially when you add the cost of an adaptor.) It is still a viable option if the performance is there and I assume it would balance nicely on the end of a 7. 

[phrunt]

It weighs next to nothing on the GPZ, I can't remember the weight, something like 800 grams, it's on their website, but I'm probably not the best person to ask as my soils are mild, but for me the 8" is as good if not better than the 6000.    I did some air test videos showing its differences to the GPX 6000 on Youtube, and in those it's performance was very clear but I can run the GPZ in normal.

We have hot rocks here but no doubt they're different to yours, I find the 6000 worse for them than the GPZ with the 8".  

In saying all of that, do you need one? with a 6000 and 10x5" probably not.  The ideal candidate for a smaller GPZ coil like the 8" or 10" is someone that doesn't want to have to buy a 6000 to get the small gold performance of a 6000, significantly cheaper to buy a coil and get an adapter made than buy a 6000.

I just wish Minelab would give in, disable the chip and let the aftermarket coil manufacturers go for gold on the 7000.

If you wanted more depth, with near GPX 6000 sensitivity/depth to very small gold the 15" Concentric coil is probably a better choice, it gives near 6000 performance on small gold with superior GPZ style depth on bigger stuff.  

I don't like recommending coils for people though, as my soil conditions being mild maybe very different to someone elses, I just know what works best for me, best thing to do is ask around, far more 15" CC users than 8" users though, most don't care enough about finding the tiny bits to justify an 8" when the 15" is close but deeper on all else.