Garrett 24k Maiden Voyage

[phrunt]

We've been in a bit of a Covid lock-down recently and during that time my Garrett 24k arrived so I wasn't able to use it in the gold fields straight away, it was quite painful to look at it knowing I can't go and use it, fortunately we came out of our lock-down and as took off for a prospect with the 24k as soon as I could.

I ordered a White's 6" concentric coil for it to tie me over until Garrett and with any luck Nel come out with other coils for it, I hope they continue with the 6" Concentric as I'll buy a Garrett 6" Concentric as soon as they release it. It's a remarkably sensitive coil, I expected it to be less sensitive than it is as it's quite big however it surprised me and matches or exceeds smaller coils on other high frequency gold detectors.    I've always been happy with Garrett coil quality so upgrading the Whites to a Garrett would be worthwhile I think.  In saying that, neither the 10x6" Garrett coil or the Whites 6" coil were at all bump sensitive, not one bump noise the entire day.  I'm so used to coil bump sensitivity from the Equinox and Gold Monster it was a rather pleasurable experience being able to scrub the coil on the ground like mad and bump it around not setting off the detector, giving me a distinct advantage over using bump sensitive coils. 

I started the day using the 10x6" Coil as I wanted to see how it goes and I was going back to a spot I'd found a fair few grams of gold in the past, about 30 or more nuggets using the scrape and detect method taking off layers of soil at a time and detecting it.  The initial nugget which was just under half a gram and a fair few more were found using my GPZ including a 4.2 gram nugget and then I brought in the Equinox with 6" coil to clean up as a majority of the nuggets were very small and the VLF's tend to do better cleaning up these very small nuggets.  I'd even gone over this little scrape and detect area with the Gold Bug 2 however it was a bit of a nightmare as the area is absolutely full of hot rocks and the Gold Bug 2 in heavy hot rocks isn't a good detector in my opinion, it's too busy making it's response noise to the hot rocks to worry about the bits of gold next to the hot rocks so you miss nuggets if they're near hot rocks.  The problem is this spot is loaded with hot rocks all through the soil of various shapes and sizes mostly a green type of schist that is all crumbly and broken up and detectors love to sound off on it.  It's likely there from the old timers, it's basically some old workings where the old timers left their rock pile in a little gully, and right on the lower downhill side of the rock pile was my little scrape and detect patch.   Even the GPZ struggled with all of the hot rocks so I was quite pleased how the 24k was coping with them, sure it was sounding off on some of them too but it wasn't too troublesome and seemed to ignore the little broken up bits and very usable.

I ran the 24k with the sensitivity maxed out, Sat on the middle setting and audio on Boost 2.  The ground balance was quick and easy then I switched into the Locked balance mode.  If the broken up schist bits of hot rock were too severe I left it in tracking which helped to knock them out.    I gave the 6" Concentric coil a quick try and it struggled more with the hot rocks and i didn't want to lower my sensitivity down so I reverted back to the DD which appeared to handle them better and is still remarkably sensitive.

So I just started scraping back layers and detecting taking about 2 inches off at a time knowing the gold here is likely going to be very small and it will be stuff I've missed in the past as I've scraped this spot out before and back filled it so I was essentially checking the same soil all over again for anything I missed.  I had high hopes I had missed some as all it would take is a small hot rock to be sitting on top of the bit of gold the previous time and I'd likely miss it or just the bit of gold on it's side being a very thin one or any number of reasons, even just at a depth too deep for the size of gold with the detector I was using.

It wasn't long and I had my first piece.

Quite a decent size one too, I was baffled at the time why I'd missed this one in the past.  The 24k had now found it's first gold, highly likely the first piece of gold found in New Zealand with the Garrett 24k, a badge I'll wear proudly. 🙂

Next up was a reasonably faint but very repeatable signal with no target ID showing, I delicately used my scoop to scrape soil away knowing this was likely a very small bit of gold and it sure was... my smallest bit of the day too and surprised I managed to find it with the 10x6" coil, I don't recall ever finding a bit this small using the 10x5" type size on other detectors.

Can you spot it? 🙂

There it is!

0.007 of a gram, not bad for the 10x6" coil, especially in this hot rock infested ground.

I always check targets in case they're odd little bits of metal with my pick magnet, and you'll see it was quick to build up black sand, this soil has plenty of it in it.

I kept scraping down layers and found another.

Quite small too... but a bit more meat on it than the previous one 🙂

I'd had enough of the scrape and detect spot by now and wanted to go explore a bit to see how the 24k performed for general detecting so I walked for about 10 minutes to another spot I'd found some gold in the past and detected for about an hour digging plenty of shotgun pellets, completely normal in this area as there is a rabbit plague that causes countless thousands of shotgun pellets to be distributed all over the place for me to clean up 🙂  I didn't have high hopes as myself and a friend (JW) have absolutely thrashed this area but it's always possible to miss gold when there is so many pellets.  We generally scrape a few times and if the signal persists dig it, if it moves after the first scrapes ignore it thinking it's very likely a pellet.

A few pictures of the sort of terrain I was detecting.

My batteries went down to 2 bars quite quickly, within an hour.   I assume as they're rechargeable and run at 1.2 volts instead of 1.5 volts for standard AA's but it stayed at the two bars for the entire day so still plenty of life left in them yet by the looks of it.

Pretty wild rocky terrain and only really suitable for smaller coils.

The GPZ with it's stock coil is terrible here, the smaller the coil the better in general.

I did manage to find a piece though, after a lot of pellet digs 🙂

Not a bad size bit for the area too

 

I now decided I'd put the Whites 6" Concentric coil on and give it another go as this area doesn't have near as many hot rocks as my scrape and detect spot.

I found a bit of raised bedrock and had a signal that persisted down into the schist.  At this point it almost had to be gold so I started filming.

And it was gold 🙂

I had to break up the schist to get it out.

A nice little piece too, a roundish flat one.

This area has plenty of black sand too, this was my pick after checking that bedrock in case it was a steel shotgun pellet.

It was getting near time to go get some dinner and I was pretty satisfied to even get one nugget in this area but I kept going a little while longer and it paid off.  I like the bulls eye sight on the 6" coil, it really is the hot spot too, great for pinpointing.

I had a signal that persisted down into the gravels on the bedrock.

And got this one!

It's hard to tell the depth in the photo but it was a reasonable depth.  A few inches anyway.

And that was it for the day, I was starving!

So, do I like the 24K? You're damn right I do, it certainly exceeded my expectations and will now be my primary VLF gold detector replacing my Equinox which replaced my Gold Monster, and the Gold Bug 2 was just not for me, I didn't gel with it at all especially with the masking from hot rocks.  I look forward to getting more coils for the 24k, especially smaller ones, and judging by how well it handled the hot rocks I wouldn't mind a larger size coil for ground coverage too.

The total for the day.  Very happy with the results.

[mn90403]

Well done and told Simon.  I'd say you have a keeper there for you area.

[F350Platinum]

Bravo phrunt, That's a great looking detector too. Looks like Garrett has the gloves off for the fight now. 👍

[water spider]

wow! informative and impressive, well done thank you

[Steve Herschbach]

Great first outing Simon!

Leaving ground tracking on instead of locking may help with the hot rocks while still getting the gold. Use a tiny test nugget to experiment with both tracking on, or locked. A hot rock should track out immediately, while a nugget does not. Though as you know the tiniest nuggets may track out also. You really need a tiny test piece to experiment with. I keep a 1 grain (0.0648 gram) nugget taped to a business card for just that purpose.

You can also try ground balancing directly on a hot rock while in locked. The new XGB ground balance system tracks to a wider range of targets simultaneously than the older White's systems (see the White Paper below). The XGB balance will sometimes reject them completely, while still ignoring the ground. Other times, the rock my go away, but now the ground signals. If that’s the case, try swinging widely over the ground, and a rock, to find a medium balance that reduces both. Slightly lowering the sensitivity and/or increasing the SAT at the same time can help find the perfect setting. It takes some experimentation with that test piece to find the settings that best handle ground and rocks, while still getting the nuggets. It’s a judgement call sometimes, as when the hot rocks are few, then digging a few might be acceptable, allowing hotter settings. In thick hot rocks, a more aggressive setting that reduces hot rock signals may be called for, even at a small loss of gold signal.

The is also a ground balance offset, that can be applied to both tracking and locked. Tracking and ground grab (Garrett calls it ground sync or quick balance) seek a neutral setting that may in fact not be just right for the hot rocks, and you can actually adjust the preset track or ground grab point up or down. You have to go to the Ground Scan mode, and then use up and down arrows to apply an offset. Then switch back out of Ground Scan mode, and this offset will carry over, and be applied to both tracking and ground grab (ground sync) settings. Instead of using a wide swing to try and find a medium balance, you can ground balance directly to the ground. Then experiment with different degrees of offset, to see if you can lessen the hot rock signals, while still keeping the ground quiet. The right offset can do wonders in some locations. Again, slightly lower sensitivity and/or increased SAT can be part of the mix.

My old mentor Jimmy Sierra likened it to adding salt and pepper to the stew. It takes some experimentation and tasting to get the seasoning just right. A lot of what applied to the GMT applies to the 24K, and you can see the full set of Jimmy’s old videos at this link. Unfortunately the video quality is poor, but the information is gold. 

I doubt this applies in your ground, but people who have severe enough iron stone hot rocks, will find going to disc mode, and setting up two tone discrimination, will be the magic solution. Most hot rocks can be set to give a low ferrous tone, while nuggets will give a non-ferrous high tone.

Final tip, in low mineral ground with no hot rocks, max sensitivity and SAT at lowest setting, and moving very slowly gives you even more power. Autotune or Self Adjusting Threshold (SAT) Explained

This may all seem complicated, but these are all just extra settings and tricks a person can apply as they get more experience. That’s why I like the 24K more than some other dedicated VLF nugget detectors. It has super simple settings for the novice to get going, just like the others. But it also then has a multitude of settings that can be applied to fine tune the machine. That, plus the “not knock sensitive” coil selection, that allows for scrubbing techniques, makes the 24K a winner.

I honestly do like the Equinox also for the most of the same reasons - all the adjustments I can make. It’s a great nugget machine if you can master the settings. Where the Equinox falls short is coil selection, and coil knock sensitivity. The 24K already has a superior nugget coil selection, and once Garrett and NEL get the full component of coils out, the 24K is going to blow Equinox away for coils, especially the solid type (not open web) coils nugget hunters generally prefer. And call me old fashioned, but for bush work there also are times I don’t want a rechargeable detector, but just want to swap out the battery pack. 24K suits me there also.

GOLDMASTER 24K WHITE'S PAPER

XGB - A New Way To Ground Balance

The biggest challenge we face as electronic prospectors is highly mineralized ground. Simply increasing the gain on the current VLF platforms might help prospectors in very mild ground conditions, but what about more difficult areas with concentrations of black sand, maghemite, serpentine, or alkali salts?

On a trip to Brazil we witnessed a combination of these conditions, with soil that ranged from red to black to purple, and exhibited a combination of ferrous and alkali properties within a 4 ft square section. We saw first-hand VLFs from each manufacturer fail to balance out the combination of minerals. Even the top-of-the-line pulse induction machines struggled in this area - machines which cost the garimpeiros (the local term for gold miners) several years’ wages.

Our goal was simple: a nice even threshold in challenging ground conditions without giving up sensitivity. The theory is that the main battle most electronic prospectors fight is being able to discern a potential gold signal from ground noise. A smooth threshold would allow users to use more gain and increase their odds of finding small gold where it likes to hide - in mineralized ground.

The issue with other VLF detectors on the market is that they were tracking a single ground balance point. When the ground type changes quickly, the machine gives off a false signal. For a user the result is ear fatigue, frustration, and less positive signals dug. One easy way to mask variable ground is implementing an auto-gain feature that automatically numbs the detector. This does not solve the issue, only hides it.

The Goldmaster 24k’s XGB is a new automatic ground tracking system that works by tracking multiple ground points simultaneously and quickly. Where other VLF’s track one ground balance point, the Goldmaster 24k tracks several, and can determine an optimal “ground window” based on ground history and strength. This is very useful in rapidly changing ground conditions, where other VLF machines may struggle to track the mineralization changes. Combine this with the speed at which the Goldmaster 24k is able to grab ground samples, and you have a superior ground balance system for a prospector’s VLF.

XGB Ground Balance versus legacy methods

With any automatic process, there are some concessions. Take vehicles for example - manual gearboxes are still preferred by car enthusiasts. That’s why we felt strongly about including a TracLock® ground option. When used with the Ground Grab, a locked ground balance setting allows users to set the ground balance in an area and lock it until they need to re-ground balance. For users after the tiniest bits of gold, this option allows for the maximum sensitivity to small signals.

One technique we observed from field testers was allowing the XGB to automatically track, and then  after getting a solid hit or finding a patch, locking the ground balance for target location and retrieval. For many users this combination will be the best of both worlds - the strength of XGB, but only when you need or want it.
 
The net result of an overhauled automatic ground balance system is a VLF gold nugget detector that can  be used in a wider variety of ground conditions with a nice stable threshold. Operating a machine with a smooth threshold allows for a user’s ears to tune into those slight variations that just might be the next nugget. Our goal is that our customers are able to have success with the Goldmaster 24k in areas that other VLF’s struggle, and at a price that allows more people to get a taste of electronic prospecting.

Tom Boykin
White's Project Manager

[phrunt]

Outstanding post Steve and one I'll print out and read over a few times and even take it with me next time I go to this area, I took it to this spot knowing it was up for a challenge and I was hopeful I'd find gold I'd missed with the other detectors that all struggle here on these green schist type of hot rocks.  I'd previously done a post requesting help with the GPZ struggling on them when I originally found this scrape and detect spot and with JP's advice was able to tame them a bit, but they were always still a problem.  I had the 24k handling them quite like the GPZ was with minimal settings adjustments.

I basically ran the machine as a beginner first time user and managed to get it working to a point It found me gold by adjusting very few settings and was very happy with the results so even though the settings are there when you're comfortable using them and have a better understanding of the detector it really can be used on as a switch on and go detector and perform very well. 

Now I'll start to experiment and learn about the settings and adjust it to get even more out of it.   To say I was happy with it is a bit of an understatement, I was very surprised how well it did.

Having the settings the 24k has will be invaluable in these challenging areas and for me to get 6 pieces of gold there was rather odd, I'm normally lucky to get one and often go home empty handed.

[GB_Amateur]

Great report, Simon, and congrats on finding a 0.1 grain(!) 'grain' with a 6"x10" coil.  (I don't think that even qualifies as a picker, it's so small.)  Of course we all (and obviously you in particular) hope for much larger ones.  😉

It's gotta be a plus to have a detector which can be fitted with either a DD or a concentric (or Mono in the case of PI's) as the conditions warrant.  I'm glad White's and Garrett never forgot that.  It's going to be very interesting to watch as Garrett and NEL/CORS produce more coils for this detector and detectorists like you and Steve H. figure out how to maximize their use.

[phrunt]

Yes, coils can make or break a detector I think and it's really great having both Concentric and DD to choose from. 

It's great finding bigger nuggets but I get a real thrill out of finding the tiniest pieces, it's really exciting to recover the really small ones, the challenge of it is a real thrill.  I think I get just as excited about very tiny bits as I do bigger ones as the technology to find them is just mind blowing.

The smallest one was so small if I was to breathe on it I'd lose it.  I had to be so careful putting it on the coil at the end of the day for the total photo as the wind had picked up a bit 🙂 The only way you can pick up bits that size is to wet your finger so it's weight is likely less than what the scales say as I'd wet my finger to put it on the scales, the water on it had to add a fraction of weight when the bit is that small in the first place.

Garrett Search Coil Tech Sheet

About Search Coils by Dave Johnson

Search Coil Field Shape by Dave Johnson

Coil Basics by Carl Moreland

[Steve Herschbach]

I added some coil links to your post above Simon. The short story is this. The concentric hit the hot rocks harder because that is what it does - hits harder. Not good where you have hot rocks, but it also does mean where you can use the coil, it has extra punch. And if anyone reads the tech info above, they will see that a DD coil is more likely to call ferrous items non-ferrous, especially flat steel. So a concentric has better properties in trashy areas.

Can't wait for NEL to produce the 3.5" x 6.5" Snake DD coil for the 24K. That may be a perfect coil for the machine, especially as it has been especially hardened for use without a scuff cover. When chasing the tiniest bits I do tend to run my coils naked!  Seriously, it's halfway all about how close you can get that tiny bit to a coil winding that makes the difference in mild soil. And scrub, scrub, scrub!

https://www.detectorprospector.com/magazine/steves-mining-journal/metal-detecting-micro-gold-nuggets-crow-creek/

[Dances With Doves]

Great info by all of you.The X-terra 705 had tracking offset over 10 years ago.A snake size coil in both concentric and in DD would be  nice. Garrett has a 3 by 7 coil mold they used for the  infinium.Steve did a report on that coil.My 4by 6 dd whites coil is not smooth like my concentric so i will get a snake coil for it. I need  a epoxy coil for my  GMX for the water.Simon you do need a snake coil for the terrain that you hunt with all those rocks.Also Steve should  have the smallest nugget  of the  month award contest. I also bet that for every gold bug 2 that is sold today there are 100 24 k's sold.