60 ounces missed by ML4500 and 5000

First topic message reminder :

Here's our story of woe from this years operations. This patch was originally found about three years ago when we heard about it. It was on company ground but we decided to apply for a Special Prospecting Licence and give it a good pushing. Of the 60 ounces found by the orginal finder, very few of the species could be heard with a ML 5000. 95% of the gold was found with a Whites GM2. These White's machines are not pulse induction. They belong to the "outmoded" (?) VLF type of detector.

We knew of this phenomenon so we bought a Whites for the job. After getting the SPL and all the permits from the DMP and DIA, we pushed in 4 spots to a depth of 400mm,,,,,,,,,and came up empty on every scrape. After this disappointment we decided we'd "surf the surface" with the Whites. With this we found 8 species,,,,,,,,,only one of which could be heard with a ML4500/5000 when tested. All the species were on the top when found and all screamed at me with the Whites.

Not one specie was under the surface. They were all sunbaking, but the ML machines went clean over the top of 'em. All were very well rounded and worn. As you can see, the gold was extremely fine and this is the reason that an ML Pulse Induction machine can't "see" it. More with the next photos.


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This is an interesting thread for all.  Just some words which maybe have been misconstrued.  Carry on fella's, I want to hear the rest of ya thorts on PI versus VLF.
I got an old ML XT17000.  If I remember correctly it had two Hz settings, 6.4hz & 32hz.
I wonder how it would go today.

So could one take from this rationale then that in certain circumstances a VLF will out perform a PI machine as was the case with the species.

Not to mention the VLF searching for a more specific size target optimum to it's current working(coil size) frequency...meaning no off time ?,as with the PI .

PI has it on multiple size searchable targets ....
Vlf faster and probably deeper on right size target matched to coil n frequency .

The Deus has 4 different frequencies ... 4k - 17 k
Wonder how this compares in the VLF world as they promote it with a REACTiVITY setting that makes it faster than most.

Chad,
 
I have no design plans for my little test dryblower. It was designed in my head on the "looks right" principle and drawn up in chalk on my steel bench top then wiped clean at the end of the build.
It folds down into a 400mm high x 400mm long x 250mm wide module and weighs 19 kg. The 12v motor draws 2.5 amps or about the same as an Engel Fridge.
 
I wanted one that was compact and light for testing. Then use my bigger one if I got onto a bit of dirt.
 
PM me if you want some pictures, you should be able to use the design from the picture.
 
Driller.

I think you guys need to also think about 'Time constants', if a target loses its Eddie current before the switch on can receive it the detector will be blind to it. If you want to ignore mineralization you need to have the switch on time happen after the ground noise has dissipated; this is the true reason why some speci's fall into a PIs blind spot, the target signal dissipates away in around the same time frame as the ground signal does.

JP

Wow man , thanks for the latest mythbuster mail , il try it out .

Jonathan Porter wrote:I think you guys need to also think about 'Time constants', if a target loses its Eddie current before the switch on can receive it the detector will be blind to it. If you want to ignore mineralization you need to have the switch on time happen after the ground noise has dissipated; this is the true reason why some speci's fall into a PIs blind spot, the target signal dissipates away in around the same time frame as the ground signal does.

JP

And there you have it! From the pen of the Master himself, the Minelab Tester, Jonathan Porter. If the eddy current isn't "big" enough then it'll die before the circuitry can switch "on" and "listen".

Cat

So in the case of the patch of fine gold species where the PI's missed it, can I assume my old VLF XT17000 just might be able to pick it up ?
I'm guessing the old machine might still be of use.

ar ... you guys ... not takin the piss .... just sayin , why turn a dumb cnt job into a complex task , jees ... swing swing .. beep beep .. dig .. dig , that's all it is & im allowed to say it after several hundred oz

Swing Swing Beep Beep dig it up and find a couple hundred ounzes, not everyone is in that class. So every little bit of knowledge helps people in the crazy search for gold.

Didn't mean any class factor Cliff , just mainly trying to relate to newcomers that you don't need the latest & greatest gear & I was usually 2 years behind & still got it . The best results are from new ground , or following a dozer which is a rare opportunity . New operators can be misled into thinking because they spend a fortune on the best stuff .. settings this n that , they will get the gold, not the case at all .

Point taken albo.  I just got a 5000 to add to my arsenal and there was no way I could master that machine in the 2 days I had in Leo.  But ya gotta try.
you are right, you don't need the new machinery on the block to find ??? what is it we are looking for again    
If I'm not careful, I'll get gold fever again  

wow, Cliff got the 5000 ,big jump from the extreme mate, can you give us an unhyped up report on it after you get used to it Cliff ,cheers albo.

Just to add my 2 cents albeit late in the day, I tried my hardest to detect these speci's from Cat's area with my 5000, I used an 11in mono commander coil and a sadie from nugget finder. I used every possible combination of settings that I could possibly think of and I couldn't get a response from the speci's whatsoever. One piece had multi ounces of gold in it and the 5000 didn't even give a whimper. I wouldn't however throw away the 5000 just yet, when the patch was originally worked there were quite a few speci's that were detectable with a 4500-5000 and were picked up, all in all 27 speci's were picked up off the grid lines of a 4500 & 5000 , the whites GMT went over the exact same grid lines after the 4500 & 5000 and an additional 173 speci's were found!
So my advise would be if you have found a patch where the gold is peppered through the host rock in such a way as Cat's examples is borrow a GMT or other such VLF machine and have a swing....you never know what you will find!

& Cat I hope your doing well, sorry for the lack of correspondence of late----just been hunting for new areas for summer and have basically been lazy answering emails/calls etc. The winter has gone pretty well and I have no complaints, everything has been plodding along like it has been although i have added a new tool to my prospecting arsenal...a Holden Rodeo 4x4....so im now able to get out in the back country and have a look around. Anyway ill give you a call when i get back from my little prospecting trip a couple hours north.
cheers
carms

albo wrote:wow, Cliff got the 5000 ,big jump from the extreme mate, can you give us an unhyped up report on it after you get used to it Cliff ,cheers albo.

I can give you an unhyped up report right now.  It's a mongrel of a thing     I like switches and dials and the 5000 takes some learning.
I read a lot about the settings and had them too high.
One thing I did learn and can tell ya's, depending on the type of ground,  keep ya settings low or the machine is "Noisy as Hell" and will drive ya crazy.  
It takes some getting used too but like I said, ya won't work out how to use it after a few hours of detecting  

 
Cliff
PS.  this story is courtesy of the brilliant author named "where am I, beware of home brewed Rum "  

Steve,

Thanks for the support on the thread and believe it or not you've added heaps to the story of that patch. I had no idea that so many species were found there. I only saw about 50 in glass jars.

Cat

Great post Cat,clearly showing the superiority of VLF's under those particular circumstances.I know Jim Foster,in one of his CDs, mentions a area up Laverton way that is the same,where VLFs have the advantage over PI's.There must be other areas in WA where the same is true but haven't been discovered yet.Don't be surprised....Trev.

this is amazing, Karen, my wife uses the old VLF machine as we can only afford to hire one 5000 on a trip, Hmm maybe the "hotrocks" she kept finding could of been fine gold bearing species...   better take a closer look next time  must be a lot of gold left behind in those areas apparently cleaned out. I bet this has got a lot of ya thinking of some old ground to revisit.

with the 5k, form my limited use I agree it takes some learning, seems to take me 3 to 4 days to get it right for the area... as for the settings I did the autotune and had a lot of noise from the machine, Col suggested turning the frequency down to around 70, I got the same advice from another fellow. I did this and this seemed to work well and then I found small pieces, one at 0.07g 3 inches down. whats your thought on using the higher range over the lower and what difference does frequency make?
thanks for the advice
Martin

albo wrote:Didn't mean any class factor Cliff , just mainly trying to relate to newcomers that you  don't need the latest & greatest gear  & I was usually 2 years behind & still got it  . The best results are from new ground , or following a dozer which is a rare opportunity . New operators  can be misled into  thinking because they spend a fortune on the best stuff .. settings this n that , they will get the gold, not the case at all .

Spot on Albo

The ability to use a detector in the GPX range only comes with many, many hours on the ground. You can read volumes on "how to" but nothing takes the place of personal experience.
It's like obtaining a pilot's licence. The first day in the seat looking at all those dials and switches is daunting but , in time, you learn their functions and limitations.
Someone who goes out detecting three or four weekends a year cannot be expected to master the GPX.
My wife and I have spent literally thousands of hours with all the GPX's and we are still learning things.
You must master two things to be a successful detectorist. Your detector and equally important... your environment.

Robert

well after we clean out the riffle trays in the dry blower a mate stuck his 8x6 in the tub to see what would happen and yes it screamed..pieces of gold as big as .3 of a gram..

but when we detect the exact same area --zip -- stuff all.

nearly cracked the 10 oze mark all fines and a few chunky bits..

regards
oneday

A 6inch coiltek Sadie coil will find the sunbakers and small stuff near the surface using a ML5000. I recently purchased one one and have found gold pieces that don't register on the digital scales. It finds the gold that you would normally walk over using a bigger coil.

Sorry that was supposed to say nuggetfinder, it's been a long day folks...

......... I did this and this seemed to work well and then I found small pieces, one at 0.07g 3 inches down. whats your thought on using the higher range over the lower and what difference does frequency make?
thanks for the advice
Martin

Iv played with this over the years and have never been able to convince myself of any benefit from the hundreds/thousands of undug targets in which i tested it over. I think its more of a "feel good" setting, sure on  occasions the auto-tune may get it wrong, but to say the detector is able to hear nuggets from one tune decimal to the next would mean the detector has one hell of a flaw. Say for instance you never touch the manual tune, and only ever operate where the auto tune pulls up, could you be that unlucky it pulls up on a freq that nuggets dont signal on.?? Sounds corny doesn't it?...but thats whats being suggested.

I wouldn't get into the rut of thinking you must have it set on a certain number, or someone will come along and  burst your bubble and show you the error of your way. Iv seen it and the operator will put up with a detector thats as noisy as hell, rather than listen to reason because they believe without a doubt, its gospel.

The auto tune takes about 60sec to perform a function the inverter thought had merit. It takes time to write the program and factor in alot of what we dont understand about the regime. Id hazard a guess and say in the programing there is a set of Ones and Zeros thats factor in this very scenario and allow the detector full detection capabilities through the setting 0-255. While the number scale appears large, the frequency swing from memory is very small. A pointless function if it did discriminate on certain frequencies.  

At the end of the day....if you feel it makes you a better operator...let no one tell you different.


PS. When the auto tune function has been initiated, a detector in range is effected, this tells you the tx side of the function is also being shifted. Does the shifting tx freq return to its set value at the end of its cycle, or does it lock in with the rx.?  

Glad we got experienced 5000 users here,  Let me see if I got this right.
Ya auto tune first.  
then ya turn ya knob left or right depending on the hang or the gain but,  make sure the knob ya gained is stabilized.    
What ya do then is whack it on the ground, hope it doesn't hurt and get balanced      
But then ya have to choose what coil to use       

  1st then rig up damn yaz     

Bignuggs, do you use a booster? They work well if your happy to run a speaker or two. As for the VHF's vs PI no doubt they both have a place as does all size coils and utilising the different timings. Will you always leave behind gold? For sure but the more combinations you use the better off you will be. Having spare coils with a lower shaft on speeds things up. Plenty of time swinging the coil over the ground helps.