Garrett 24K In Ironstone Type Ground

[Tony]

Not sure if this has been covered before but I’d love to know how the Garrett 24K can handle heavily mineralised ground such as that found in Western Australia. Looking for fairly shallow nuggets amongst eye popping amounts of old iron trash targets. Yep, I’ve tried the Minelab PI machines with small DD and mono coils but I nearly threw myself down a mineshaft such was the frustration. I’m thinking a 6” sniping style coil is the way to go.
Thanks for any advice,

Tony

[Off Grid]

Is the problem metallic iron trash, ironstone or all of the above? My gear is different so I can't offer a solution but you are not alone! Tried a new area last week, laterised ironstone-rich terrace gravel over weathered dolomite and both my VLF and PI struggled. Had to run the GB2 in iron-discrimination mode and the ATX really struggled to ground balance. I found myself wondering if the Garrett VLF at 24k would offer a material improvement over the 71k GB2. Will follow this thread with interest.

[Valens Legacy]

I believe the write up that Steve did a few weeks ago when he got back from Alaska should help you understand the 24k's abilities. Alaska does have highly mineralised  ground when detecting and he gives a few pointers on how to solve most problems. If this does not help I am sure that someone will be able to help more than I can.

 

[karelian]

The 6 inch concentric coil on the 24k/GMX is fantastic, excellent in moderate ground but still usable as  the ground gets hotter. For hot ground with trash, the 6x4DD or an equivalent would be a better choice. A time goes on there may be more coil choices available. WA is an area that makes any VLF hard work, not sure the 24k would be any different. For exposed bedrock, surfaced areas or very shallow ground the pain may be worth the gain. Trashy areas combined with very nasty ground, I'd walk away or reach for my MXT with the 6x4DD. I know the MXT well and have more confidence with it in such a demanding scenario. A few more hundred hours with the GMX, maybe I'd have a go. 

Tony, put that small coil on the Xl Pro, run in hot rock reject,  SAT GEB, with low gain and see how it goes. I took mine out to Dunolly for a run, found a six pence and a half penny hidden among trash. A bit of fun. It's old tech but it id's iron well enough.

I'd be very interested to see if the old girl can run smooth on the Mars landscape you have out West.

 

[Tony]

1 hour ago, karelian said:

The 6 inch concentric coil on the 24k/GMX is fantastic, excellent in moderate ground but still usable as  the ground gets hotter. For hot ground with trash, the 6x4DD or an equivalent would be a better choice. A time goes on there may be more coil choices available. WA is an area that makes any VLF hard work, not sure the 24k would be any different. For exposed bedrock, surfaced areas or very shallow ground the pain may be worth the gain. Trashy areas combined with very nasty ground, I'd walk away or reach for my MXT with the 6x4DD. I know the MXT well and have more confidence with it in such a demanding scenario. A few more hundred hours with the GMX, maybe I'd have a go. 

Tony, put that small coil on the Xl Pro, run in hot rock reject,  SAT GEB, with low gain and see how it goes. I took mine out to Dunolly for a run, found a six pence and a half penny hidden among trash. A bit of fun. It's old tech but it id's iron well enough.

I'd be very interested to see if the old girl can run smooth on the Mars landscape you have out West.

 

Thanks for the reply….and of course that beautiful XL PRO that you kindly sold me. You’ve got me thinking about that suggestion…6.59 KHz with the small coil. It’s brutal ground…..highly mineralised clay/calcrete with purple ironstone and assorted hot rocks…..add in the man made iron trash……now go find small nuggets 😳 

I’ve also got the little powerhouse MX7……based on the MXT circuitry.

Maybe a solution somewhere ?

 Thanks 

[Jim McCulloch]

Tony, thanks to the XGB system the 24k handles mineralization far better than any other VLF operating at a similar frequency, including it's predecessor, the GMT. On my 24k I use the 6" concentric most of the time, and it has no problem operating in Mojave Desert black sand washes. What is really astonishing is that the 24k works flawlessly even with the huge 14x8 coil. Check out the video "White's GMX and 24k: ALL 4 coils tested" on Rob Johnson's "Spud Diggers" YouTube channel, where we do an in-ground comparison. To see how the 24k fared in Idaho, see Rob's "Metal detecting a gold mine - gold, bottles an relics found." HH Jim

[Tony]

9 hours ago, Jim McCulloch said:

Tony, thanks to the XGB system the 24k handles mineralization far better than any other VLF operating at a similar frequency, including it's predecessor, the GMT. On my 24k I use the 6" concentric most of the time, and it has no problem operating in Mojave Desert black sand washes. What is really astonishing is that the 24k works flawlessly even with the huge 14x8 coil. Check out the video "White's GMX and 24k: ALL 4 coils tested" on Rob Johnson's "Spud Diggers" YouTube channel, where we do an in-ground comparison. To see how the 24k fared in Idaho, see Rob's "Metal detecting a gold mine - gold, bottles an relics found." HH Jim

Thanks Jim…….I’ll check out those videos for sure 👍

[Steve Herschbach]

On 8/28/2021 at 6:22 PM, Tony said:

Not sure if this has been covered before but I’d love to know how the Garrett 24K can handle heavily mineralised ground such as that found in Western Australia. Looking for fairly shallow nuggets amongst eye popping amounts of old iron trash targets. Yep, I’ve tried the Minelab PI machines with small DD and mono coils but I nearly threw myself down a mineshaft such was the frustration. I’m thinking a 6” sniping style coil is the way to go.
Thanks for any advice, Tony

Some ground is just very difficult to detect. If you can’t get a PI to settle down, I’m sure a VLF will also be challenged. The key is the one thing people hate to do - reduce sensitivity until the detector is stable. Small coils are also helpful. At the end of the day you simply have to accept whatever performance you can get from a detector, and there is actually a reason the sensitivity controls go as low as they do. So will a 24K work? Sure. Will you be happy with the performance you get once you dumb it down enough to make it stable? Only you can answer that one.

[Tony]

7 hours ago, Steve Herschbach said:

Some ground is just very difficult to detect. If you can’t get a PI to settle down, I’m sure a VLF will also be challenged. The key is the one thing people hate to do - reduce sensitivity until the detector is stable. Small coils are also helpful. At the end of the day you simply have to accept whatever performance you can get from a detector, and there is actually a reason the sensitivity controls go as low as they do. So will a 24K work? Sure. Will you be happy with the performance you get once you dumb it down enough to make it stable? Only you can answer that one.

Thanks Steve,

I’m fully realistic about the limitations of VLF in this type of ground. I might even take the old XL Pro and MX7 for a spin…….both with 6” coils and definitely with the SENS/GAIN dialled way down.

This is the type of ground where VLFs go to die and are probably buried there….which might explain a lot of the “ground noise” 😬

Strangely enough, my 2100 is one of the smoothest running detectors in this ground. We have a buried test piece and the old 2100 can’t be beat for the best target depth / noise ratio.

Love the Alaskan gold……forgot to thumbs up that post. 👍