Depth comparison between 14"GPZ coil and 19" GPZ coil. *** More Air tests Added***

Hey Reg,
As your definition of a Nugget is 20 ounces ( Mines dept Victoria definition ) How do think the 19" Coil would perform on true nuggets ( over 20 ounces ) at depth.
Should the sales staff at Minelab stated that the so called extra depth of 30 % works only on true nuggets rather than the fly sh** gold weighing less than 20 ounces?

In your highly qualified experience can anyone expect a depth increase with the 19" for real nuggets over 3 feet depth if they can overcome the other serious flaws with design, ( weight and spoked design ).

It seems to me that Minelab has responded to your requests.
"Give us a larger coil than the stock 14 inch". We wanna find a new layer of big deep nuggs.

They came up with the 19" which is likely a compromise between maintaining fair detection capability on the fly sh..t and providing significant depth increase on larger nuggs beyond a particular size.

There is no way that the 19 inch will provide noticeable depth increase on sub g nuggs over the 14 inch. It will likely come close to matching it. But I reckon you can expect pretty fair depth increase on some nuggs above 10 g.
How do I know? I guess I don't know for certain coz I don't have a Z, but am talking from more than fifty years exp with a lot of detectors and coils......So There! Naaar Naaaar, Na Naar, naaaar.

Adrian we can throw in your years of electronic experience as well.
The bigger coil should in theory detect larger targets at greater depths.

For me main reason to purchase the 19" was in the hope of finding a Larger nugget ( Reg & Mines Dept Vic greater than 20 ounces ).
As the fly sh** gold just does not get me excited as much no more.

I have a 19" only picked it yesterday, have mounted to detector, it is VERY HEAVY!
Yet to test it in the field so can,t really voice an opinion on here yet about its performance.

I think it is all a bit iffy.
Do you think that the Z and a 19 inch coil will find a large nugg (20 oncer) deeper than what the ole SD2000 or 2200D fitted with a UFO coil could go?

PI metal detectors are a strange lot in the way they respond to various size bits of metal.

For eg.
A 3 x 7 DD fitted to my Infinium will detect a 0.12g nugg at about two inches. Air Test only.
Fit the 10 x 14 mono or DD to the Finny and it will still respond to the same bit of gold at two inches.
But up the ante to 10 g and the big coil begins to gain a significant depth increase advantage that increases as the target gets larger.

So I believe that the 30% advantage that ML is claiming for the 19 inch will become more noticeable and is more applicable to large nuggs.

GPZhunter, as the only nugget in my possession at the moment is 27 ozs., I can't comment on big nuggets, however I can say that using my very unscientific tests that the 19'' coil does outperform the14'' by roughly 15%, give or take an inch. This was one trial only, and I did not vary the ground in which this experiment was conducted. Before all the experts howl me down for not doing this, or not doing that, I'm just a prospector, not a 'boffin'. It was just a rough guide as to what was going on, and was good enough for me.

Adrian, in 1966, what the hell were you playing with??? THIS DATES  WELL BACK BEFORE ANYTHING IVE EVER HEARD OF. This is earlier than Bob Sargeant or any earlier experimenter in mine detector technology in relation to finding gold?
You would have been 19 years old at that time.

Well that 15% extra can easily be the difference between finding and not finding. 

Reg Wilson wrote:Adrian, in 1966, what the hell were you playing with??? THIS DATES  WELL BACK BEFORE ANYTHING IVE EVER HEARD OF. This is earlier than Bob Sargeant or any earlier experimenter in mine detector technology in relation to finding gold?

Try 1960 with a ww2 mine detector in the Wedderburn gold fields and around Korrong vale after school at night. 
I did not know of anybody else looking for gold with a metal detector in those days. I think I was 16 or something like that.

Jeoff Proctor and myself went halves in the mine detector. 10 shillings total. Who knows, Jeoff might still have it?

Didn't find any gold with it but it was the beginning of a hobby and my interest in electronics that has continued almost unabated to this day.

Dad was the Works Foreman at the Vale railway station. I used to head off into the bush on my bike looking for gold and any unusual rocks and stuff  out as far as Wedderburn and it was after a few nuggs had been ploughed up by local farmers in their paddocks that I figured a metal detector might be a good idea. Anyway the mine detector  turned up in the Disposals store which was eventually purchased and got running. The bloody thing was powered by 67vdc battery a 45 vdc battery and a couple of gigantic 1.5vdc bell telephone batteries. The 1.5s were to power the valve filaments. All up it was a heavy unit and it just might have been able to detect a matilda tank at about four foot. 

Reg Wilson wrote:using my very unscientific tests that the 19'' coil does outperform the 14'' by roughly 15%, give or take an inch.

Hey Reg
Was this on the 27oz or was it on another smaller nugget?
What would have been the actual depth in inches and then how many more inches was that past the 14" coil point?

The next thing to try would be a comparison test with a 5000 18" coil and the Z with the 19" coil on a un dug target to see if the GPX could out preform the Z
I too have often wondered if selling the 5000 with all the gear might have been a little hasty at the time

M.

Martin, yes it was the 27, and I really can't be stuffed with further tests.

Hi all, we decided to do some more air tests with a new set of nuggets. Please refer back to the first post for the results.

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Hi all, we decided to try a different set of nuggets, as some people suggested the lack of depth was due to the stealth shape of the first set of nuggets. LOL.

All tests were performed in factory preset on low mineralised soil.

Here are the results.

Nugget size                                       14" coil                                     19" coil               % Difference

2 gr                                                  9"                                                8"                 Minus 8 %

3.2 gr                                               7"                                                6"                  Minus 12 %

5.3 gr                                               13"                                              14"                    + 9 %

6.7 gr                                               13"                                              13"                     0 %

8.7 gr                                               8.5"                                             8.5"                    0 %

10.3 gr                                              13.5"                                           15"                  +12 %

1/10 oz. Gold coin
99.99 % purity                                   15"                                               16"                 + 7 %


Sadly, as you can see from the above new test results, even with the new set of nuggets, nothing has improved. The 19" coil is still a dog. ( Good onya Reg !)

Photos of nuggets used.

This is very sad for all of us that have bought this coil on past experiences with larger coils from ML
I get mine tomorrow and I have to question my self do I even take it out of the box or not

Marty

air tests im afraid mean little with the zed. i think there is a lot more going on with the ground balance in zvt tech. if jp is reading this- would it be fair to say (although highly simplified) that the gb enables us to hear the change in magnetic field of the ground around a target before an eddy current is induced in the target as we get closer to it? this might explain why it takes a lot of digging before a sound becomes a definite target?

[quote="Martin R"]

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This is very sad for all of us that have bought this coil on past experiences with larger coils from ML
I get mine tomorrow and I have to question my self do I even take it out of the box or not

Marty

Marty, if it was up to me I would cancel the order completely. IMHO. I would happily lose the $100 deposit , than lose the $1300. If Minelab ever rectify the problem with this dog of a coil then I would buy it. At the moment, this coil is only matching your 14" coil and has the extra problems of weight, no solid skid plate and loss of ability to find the tiny gold. If you can gleen any info from your dealer about what is going on with the 19" coil, I and the rest of the members would love to hear it. Harry

I am going to wait a few months before I pass judgement to wether the coil is a fail or not........from what I can see, the 7 is a very different animal in many ways, so I expect the coil to be similar........I think air tests may be a complete waste of time at the moment, but thats just my opinion of course, until I get enough time to test it against the previous model out in the field.

Your opinion based on what Harb? When a man with the experience of kon has done the tests, and you just brush that aside; how bright is that. Please enlighten us a lttle on your success rate, so as we can appreciate your opinion.
PS Would you like to buy a slightly used bridge?

slimpickens wrote:
Marty, if it was up to me I would cancel the order completely.If you can gleen any info from your dealer about what is going on with the 19" coil, I and the rest of the members would love to hear it. Harry  

Slim this makes it even harder for than most as my dealer is also a very good mate of mine and I'd sooner loose 1.3k than that friendship any day of the week.
I shall how ever talk with him in a day or so (maybe even tonight) to talk about what others have discovered about this coil and how he went with his over the weekend just gone.

After all its not His fault as a dealer for selling goods on-behalf of Minelab Electronics Pty Ltd
ML however needs to acknowledge that this the coil may have issues and need to fix the problems at hand to those of us that placed our order on good will.

If air tests are indeed nothing to go by with the 19" coil then fair enough, but if the coil is only good for larger targets that most of us will never encounter (but hope to) then why put up a graph showing the range from 1.9g upwards, it just dont make sense, as much as I'd like to stick up for ML, from whats been written here over the past days does make you wonder and most of us are still hoping that a firmware fix will cure the issue at hand

Like many here and at other forums are some what feeling sick in the gut that they have just blown 1.3k min not to mention the full price tag to begin with

I'm gonna have a drink now and drawn my not yet discovered misfortune

Marty

Martin R ,don't accept it. If your mate is a true mate, you will soon know. If not, you don't need him. Individually they can screw us over, but united they have no chance. Have some 'fibre'.

Reg Wilson wrote:Your opinion based on what Harb? When a man with the experience of kon has done the tests, and you just brush that aside; how bright is that. Please enlighten us a lttle on your success rate, so as we can appreciate your opinion.
PS Would you like to buy a slightly used bridge?

I have absolute faith that all the tests done on here reflect the conditions they were done under 100%, but things can change given those conditions also changing.

I could tell you about many things that were in my opinion complete failures in my hands, yet a success in others.....and visa versa.

If there is indeed a failure in the coils design, I would imagine ML will have an obligation to make it right.

And if it is a fail, we are probably part of the problem putting them under pressure to deliver a coil that was not ready for distribution.

Having not yet even used the coil, I would be likened to a sheep to just take an opinion without testing myself an verifying the results so I can make my complaint based on personal experience.

I have learned a lot from the folk on here, so I value everyones opinion.......but I am pretty sure that will not be a solid enough reason to get a refund on a near $1800 coil.

Maybe I am missing something here but it appears to me that the 19 is doing exactly what I expected it to do.
Give OK response to the very small stuff and an increase in depth on nuggs above 10 g.

Maybe somebody should do a test on a 10 ouncer or larger and see what the result is.

If the 19 gave only slight increase (10% to 15%) on a nugg that size then yeah I would call it a dog.

My Infinium with the 10 x 14 Mono gives approx 24% increase in depth on a 10 OZ target over the 8 inch mono as against an approx 6% increase on a 4.7g nugg.

THe Z 19 inch being a modern squirty coil should do better than that on similar targets otherwise why bother building it at all?

We all know that no two different nuggets of the same weight give the same response and detection depth. Some may not be detected at all. So to be able to claim that a new coil has a particular detection depth increase over another coil, a target type, test conditions and  environment standard has to be adhered to.

The price of the coil is ridiculous but the market for the 7000 is tiny  while R&D tooling and  construction costs for the 19 are high. So what do ya do?

On the other hand a 35% increase in size over the 14 inch does not necessarily equate to a 35% increase in detection depth on nuggs over a certain size

adrian ss wrote:
Maybe somebody should do a test on a 10 ouncer or larger and see what the result is.

If the 19 gave only slight increase on a nugg that size then yeah I would call it a dog.

Reg Wilson wrote:Martin, yes it was the 27, and I really can't be stuffed with further tests.

I wouldn't call a 27oz piece a toy nugget

M.

With all due respect Harb, we still don't have a clue as to how successful you have been as a prospector.
Could I call myself a fisherman if all I'd ever caught were three toadies and a flathead.?

Reg Wilson wrote:With all due respect Harb, we still don't have a clue as to how successful you have been as a prospector.
Could I call myself a fisherman if all I'd ever caught were three toadies and a flathead.?

And Reg it doesn't mater at all how successful I have been.......not unless you don't have enough intelligence to make your own decisions and totally rely on my opinion to make a judgement........

I am not telling you what to do with your coil....keep it....sell it....do what you choose to....its your coil after all.

All I am saying here, is I think as a well versed person, you are 100% obligated to make you own judgement based on your findings, which is what I will do until I get a recall notice from ML telling me a fault has been found and bring it back in.

When I eventually use it and find fault, I will then be qualified to pass my experienced based opinion on if someone asks for it.

Reg Wilson wrote:With all due respect Harb, we still don't have a clue as to how successful you have been as a prospector.
Could I call myself a fisherman if all I'd ever caught were three toadies and a flathead.?

Yeh Harb come on! If you cant prove yourself to these worn out has beens ( sorry, I meant experts) then ya opinion is worth nothing!

You fellows really need to stop nit picking at each other.

Its about wether or not this 19inch coil is any good.. 
is it not??

Attack the coil.. not each other, work out between you all whats up with this coil.
Operator or coil / machine.. or none

After all dont you all want to know the answer..
also what works for some may not work for someone else
Like the ground you work on. 
Is gold still in the ground.. all that stuff.

Reg Wilson wrote:Martin, yes it was the 27, and I really can't be stuffed with further tests.

Hey Reg! Send me that 27 OZer. I like doing tests I do.

G'day All,

Just to get this back on topic, I would like to thank Slim and Co for putting up their personal test results and sharing with us here.   Thanks guys for the time that you have all put into these interesting results.  

Cheers.

Mike.

Sorry Harb, I was out of line, i just get jacked off when people with credentials do all the tests and hard work only to have others flippantly brush it aside like so many cobwebs. Sure you'll make up your own mind, but a little respect for people like kon and others that do the hard yards wouldn't go astray after all, they are only trying to save people like you and the kid from Meekatharra from foolishly throwing their money away. The way I see it, is that they are saving thousands of dollars from being wasted on a bum product.

Good on ya Reg,slim and kon for saying how it is,good or bad we all need to know,Kon must be a bit peed,you could read the excitment in his posts the last 6 months in anticipation of the bigger coil.
 After reading all this im gonna bury a few bits next week in laterite and see what happens.
 I remember when the flat wound coils came out last year or so we hit old patches with immediate results,it was obvious we were pulling more gold,same when the better half got our second gpz,she did ok on a few old spots,nothing spectacular but a bit more coming out (small stuff deeper).
 Some spots gpz is great others its just mediocre,spot we pulled about 3oz out of last month was more lumpy very scattered solid type gold,had a 2.4 bit on my 45 (flat wound 14" coil) at about 6-8" one morning,called her over,ok gpz not near the 45 signal,we tried every setting on gpz but the 45 was prob 10% better signal,i just dont think the gpz is that crash hot on deep solid gold.
 Didnt really want to buy that 19" coil but i could see it in the girls eyes she wanted one,happy wife-happy life
 Your air tests are a fair indication of whats goin on,they'll all turn up now saying its not perfect the moon wasnt aligned with jupiters southern axis or your genitals were hanging to the left that day so your tests are flawed lol
 Along with Reg's results theres a definate pattern goin on,im gonna have to bury some nuggets,yeah not perfect cause we dont like leaving mult oz bits in the ground,geez i really hope kon,you and reg are wrong but i havent got a warm fuzzy feeling about this.......

Reg Wilson wrote:Sorry Harb, I was out of line, i just get jacked off when people with credentials do all the tests and hard work only to have others flippantly brush it aside like so many cobwebs. Sure you'll make up your own mind, but a little respect for people like kon and others that do the hard yards wouldn't go astray after all, they are only trying to save people like you and the kid from Meekatharra from foolishly throwing their money away. The way I see it, is that they are saving thousands of dollars from being wasted on a bum product.

Thats Ok Reg, this subject is bound to cause massive dissapointment if an expensive tool is not doing what it is supposed to.........and damn right I will be upset too if it turns out to be a dud.......maybe I am just putting off the inevitable .

I read the tests done and totally respect the blokes doing them, and if nothing else it provides me with a very honest platform to work against............and I guess it may end up just being plucking at straws hoping things work out, but I just want to have my own story to tell when I go into battle with ML over a product that doesn't work for its intended purpose.

Lets all keep testing, loading the data here, you can only hope ML see this and use it to come up with a soulution.........and that would be the best soulution for all of us.

As a dopey Politician once said "Its all about outcomes"