GPX4500....What is the maximum depth

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GPX4500....What is the maximum depth

Post  Guest on Mon Jul 13, 2009 1:32 pm

Has anyone found a target with the 4500 in Enhance mode deeper than 18 inches?

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4500 target more than 18 inches deep

Post  jmp333 on Mon Jul 13, 2009 10:17 pm

Found remnants of a shovel head at 20 inches in Enhance in the triangle, soil was easy to dig though.
Very Happy John

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Re: GPX4500....What is the maximum depth

Post  grizzly on Tue Jul 14, 2009 8:08 am

Hi claimpeg, have found a 35 gram specie at 21" deep. I know this as I have marked my pick handle with inches on it to 24 inches. The settings were: deep, enhance, fixed, and mono on the front. I had a gain of 12 that day. Run audio normal, motion very slow and stabilizer 10 on screen. I am using a 16" round Nugget finder coil. Hope this helps.
Regards, Grizz

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Re: GPX4500....What is the maximum depth

Post  Guest on Tue Jul 14, 2009 9:01 am

Gday Grizzly

I am not surprised to hear you say that as I think that the 4500 is a very capable machine and has better depth than any of the gp series detectors so far, although I have not dug any substantial pieces at that sort of depth I have dug some specimen pieces at 12" or so.

I have also dug some smaller 1.+ gram pieces at depths of 10 to 12" too, sort of makes you feel ripped off when you find out how small they are for such a good signal, so I have had it in my mind that I dont believe you would miss a decent sized piece in the 10 to 20+ gram size at the 12" to 24" depth range using the same settings, but up until the point that you get your coil over such a target you wont know for sure.

Most of this of course if hypothetical and would depend on a lot of factors in relation to the ground type, mineralisation, position of the nugget, etc etc, and of course the size of coil you have on at the time, where an 11" mono might just see it at that depth but not respond enough to pull you up, a 16" mono will give you a good enough signal to make you stop and dig it.

Pity you didnt leave it in the ground and have a play about with the settings, the first instinct is to dig it up, but once the target has been disturbed it is never the same so testing and changing the settings may not be conclusive.

cheers

stayyerAU

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Re: GPX4500....What is the maximum depth

Post  Qld Sandy on Tue Jul 14, 2009 12:45 pm

Claimpeg wrote:Has anyone found a target with the 4500 in Enhance mode deeper than 18 inches?

I got a 41 grammer in Enhance timings using a 20" NF mono (fibreglass) coil from a measured 24". The signal was extremely faint but "there" because the rest of the ground around it was dead quiet in Enhance timings and this sounded just like a small ground noise. My mate's 18" NF mono would not signal on it until we had dug about 8" of the top, which put some doubts in my mind I'll tell you. When we were down close to the final bit I suggested we dig the hole wider as it was difficul to dig at that depth as we could only loosen an inch or so of the material at a time, but we extracted the nugget while lying on our bellies while scooping the dirt out with our hands. I actually saw it roll over in the centre of the hole as my mate scooped a handful out, and expected a piece of around 5 or 6 ounces because of the depth, but all gold is good. Cheers.
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Re: GPX4500....What is the maximum depth

Post  nero_design on Tue Jul 14, 2009 3:19 pm


Commencing the re-dig. A friend is assisting in removing the dirt that I'd dug previously but had filled back in before leaving.

ENHANCE MODE on the GPX-4500:
I've exceeded 22 inches to retrieve a flat iron fragment (5cm wide, 1.2cm thick) in highly mineralized soil. In reflection, however, there was a fragment of an old .22 cartridge closer to the surface (6" down) which may have first attracted the attention of the GPX. I can't be certain of course but it stands to reason that perhaps I noticed the metal fragment near the surface and after digging it, proceeded to detect and recover the deeper piece.

Used the 11" DD standard search coil as the soil was a little too mineralized for my Monoloop coil. Was in Enhance Mode. Had to return the following week to extract the target because it was too deep and took too long to dig it the first time out.


Junk target after extraction.

I think you'll find that Enhance Mode is better for smaller pieces of Gold but not quite as ideal for targets at depth.
_______________________________________

This is not the first time I've found a larger target accidentally whilst pursuing what turned out to be a .22 cartridge.
This Ounce-sized nugget (1 arrow) shown below was found when I dug a .22 shell (2 arrows) - which can be seen above the tip of the pinpointer probe. I ran the probe tip along the crevice and pulled out a few slabs of shale and stone to find a nice piece of gold concealed in the crack. Again, whilst the gold responded to both the detector and the probe, the .22 shell cartridge triggered a louder response from the GPX. Enhanced timings were used in this case as well.

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Re: GPX4500....What is the maximum depth

Post  Narrawa on Tue Jul 14, 2009 5:02 pm

Enhance with a DD coil..interesting, were you in mono or strait DD?
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Re: GPX4500....What is the maximum depth

Post  Jonathan Porter on Tue Jul 14, 2009 8:20 pm

Narrawa wrote:Enhance with a DD coil..interesting, were you in mono or strait DD?

Good question Narrawa, I also would like to know the answer to that question as I am of the opinion that DD's and Enhance timings in DD mode don't go together.

JP


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Re: GPX4500....What is the maximum depth

Post  nero_design on Tue Jul 14, 2009 8:23 pm

From memory, it was in Double-D. I was using it in Mono on both days though when recovering targets so there's always a chance it was in Pseudo-Mono at the time. But I know that DD was used on the second day of recovery concerning the first target because I turned on the Discrimination (low) and it took quite a while for the signal to begin to break up. I made two trips to dig that target and it was a little disappointing to find it was scrap. As I noted on both occasions above, the final targets were dig or found whilst there was a small .22 shell in between. My suspicion is that the shells acted more like 'virtual' breadcrumbs to bring me closer to the final target.
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Re: GPX4500....What is the maximum depth

Post  Narrawa on Tue Jul 14, 2009 9:51 pm

Nero....your funny! Laughing Laughing

I was using it in Mono on both days though when recovering targets so there's always a chance it was in Pseudo-Mono at the time.
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Re: GPX4500....What is the maximum depth

Post  echidnadigger on Tue Jul 14, 2009 10:57 pm

OK,
There is some sort of point to this and we have three of the best here trying to gain an answer.
Pardon my ignorance yet please be patient with me. I don't own a 4500 yet, but I do use these types of posts to gain a little education. The beaut thing with a forum is this information is archived for me to look back on.
Its obvious that there is a setting that doesn't make sense. Why?
Brett.
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Re: GPX4500....What is the maximum depth

Post  nero_design on Tue Jul 14, 2009 11:02 pm

I don't know either Brett. Some people seem easily amused.

What seems to be the problem? Enhance works best with Monoloop coils but also runs with the DDs. Sure works a treat with mine. I switch to 'Enhance' when the ground gives me too much noise to work with because this setting was designed especially for cancelling ground noise. For DD coils, the 'Normal' position is usually the preferred timing for most people, especially for targets at depth.

I was careful to refer to the DD coil being used in 'Pseudo-Mono' rather than just "Mono" because too many people here can't seem to get their heads around the difference.
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Re: GPX4500....What is the maximum depth

Post  Narrawa on Tue Jul 14, 2009 11:51 pm

I am easily amused i will admit that, but can you tell me why you needed to resort to using two types of ground cancelling?
Enhance with a DD is pretty serious stuff. Laughing
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Re: GPX4500....What is the maximum depth

Post  nero_design on Wed Jul 15, 2009 1:46 am

I have three radioactive kit markers on my detector. That's probably a little bit of overkill too.

I put on the DD coil and found it quieter with Enhance on than without in that particular area. There's a lot of hotrocks where I was. As well as pockets of individual clays that I had to dig through. Plus wash gravels and assorted rocks. The main clays were impregnated with iron which sticks to the N45 magnets like glue. Enhance Mode is good for ignoring much of it. And the DD coils is a little quieter in those types of soils by default. My only concern is losing depth in Enhance mode due to the change in Pulse frequency. I'm also not as fond of Monoloops although I have a couple which I use. Still waiting for the weather to warm up and then I can test that new Mono-monster from NF. JP won't like it though... it's elliptical. LOL!
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Re: GPX4500....What is the maximum depth

Post  Narrawa on Wed Jul 15, 2009 2:26 am

My only concern is losing depth in Enhance mode due to the change in Pulse frequency.
Im lost, you said in your other posts you were using Pseudo-Mono? thats about 5.1/2x11 coil, id be worried about depth lose as well..Laughing
Ya learn something new every day... Laughing Laughing
I have three radioactive kit markers on my detector. That's probably a little bit of overkill too.
Im vision impaired also, i know what your going through.cyclops
Best be getting back on track, sorry for the disturbance.
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Re: GPX4500....What is the maximum depth

Post  Jonathan Porter on Wed Jul 15, 2009 9:44 am

Seems like my question might have been seen as a dig, but it was serious. I would not recommend using Enhance with a DD coil in DD mode, yes it can be done but the reduction in performance negates the advantages, same can be said about using Tracking mode in Enhance which will also negate the advantage of the timing. This does not however mean you should NEVER detect in tracking mode when using Enhance or for that matter NEVER use a DD coil in DD mode when using Enhance, just that is is not recommended; there are far better options on the GPX series to combat mineralisation than reverting to such drastic measures.

The reasons are pretty simple, a DD coil removes the vast amount of the signal from mineralisation leaving a reduced response from targets left over, by then removing even more information when using the Enhance timings you can effectively blind the detector to just about all decent signals. Same goes for using Tracking mode in Enhance, once again Enhance removes the vast majority of the ground signal leaving the faint target responses behind, if you use Tracking mode you run the risk of the Tracking algorithm treating those faint left over target responses as ground noise thereby "balancing/Tracking them out" before you even hear them or tracking them out after only one or two passes of the coil.

Marco I highly recommend you taking a peek at the interview I did with Bruce Candy in our "GPX Factor" and "SETA Project" DVDs where I asked him about the timings and how they behave, very interesting stuff from the guy who should know.

The best thing about the GPX series is there flexibility, they have a Gain control for a reason and one would assume having a low number of 1 suggests you might want to use it on that number sometime, same goes for Enhance or Smooth in conjunction with a DD coil, there is nothing that says you should NOT use them together, just that it is NOT recommend. About the only thing you should NEVER do with the GPX series is run a Mono coil in cancel mode (and even this method is used to pinpoint large targets in deep holes) and that is because cancel mode and Mono coils don't go together. Other than that "the sky's the limit" with the GPX series detectors, if it can be done and you are finding gold then go for it I say, so long as you are also prepared to take a little friendly advice why sometimes you should do things a little differently. cheers

Regards

Jonathan

PS Marco I have nothing against Elliptical coils, just that my detecting style is performance based due to its direct connection with my bank account, to that end I prefer a round coil for the maximum depth it provides over an out of round design (talking about monoloop coils here DD's are a mute point), plain and simple and for no other reason. I actually get a kick out of elliptical coils because they look sexy and in some places work really well which is why I have a 24 x 12 Nugget Finder, a 17 x10 Nugget Finder a 14 x ? Nugget finder, a 18 x ? Gold Stalker, a 15 x ? Commander in two flavours (DD and Mono) and an 11 x? DD Commander.


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Re: GPX4500....What is the maximum depth

Post  goldhog22 on Wed Jul 15, 2009 10:32 am

Thanks Jonathan , The bit on tracking or fixed when useing enhanced has made my day, When I went out this year with a few friends they all told me tracking was the way to go..It didnt make sence to me as the detector would be working all the time making adjustments ect. so i left it in fixed over 300 nuggets later I say no more..Thanks again for the info...Bob


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Re: GPX4500....What is the maximum depth

Post  nero_design on Wed Jul 15, 2009 12:23 pm

Jonathan, it's been a while since I spoke to Bruce but that was a nice plug there for your 'Seta Project' DVD. To be fair to you, I placed Disc #2 into the DVD player and note that at no point was there anything mentioned (by either you or Bruce) during the exchange as to the appropriate coil selection/choice for the Enhanced timing settings. The discussion referred in general to new timings and how the new detector was handling high mineralization.


As for those coils... don't be so sure! LOL!
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Re: GPX4500....What is the maximum depth

Post  Shinegold on Wed Jul 15, 2009 4:20 pm

You might as well be using a 3000 with a dd, or an sd 2200 with a dd.
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Re: GPX4500....What is the maximum depth

Post  Narrawa on Wed Jul 15, 2009 4:29 pm

echidnadigger wrote:
Its obvious that there is a setting that doesn't make sense. Why?
Brett.
Do you understand now Brett?
Marco's settings would be better suited to looking for old axe heads & shovels.
Relic hunting perhaps.

Getting back on track with the thread topic, iv found many items at depth using the ML 11" mono, the last decent thing i dug was an old penny at Hill End the other weekend, it was 21" deep, no pics of the dig but Duckmaloi was watching.
Madtuna has also been sitting beside me whilst iv dug items at big depth with this set up in enhance.
ATM im to scared to go back to using my preferred coils, 17" NF elip & 16" NF round through fear of missing the goodies.
A question could be asked, what coil did ML base the 4500 on? was it the now supplied 11" mono as the 4500 appears to be more user friendly & mono orientated?
I with a lot of others are astonished at the depth & sensitivity that this combo can achieve.
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Re: GPX4500....What is the maximum depth

Post  Beer Beeper on Wed Jul 15, 2009 4:58 pm

Jonathan P., yes you are right, big round Mono's are more profitable being maximum depth on larger gold as you said, BUT an elliptical Mono has maximum depth being much deeper on smaller fly **** gold, if that is someones bread and butter, ever ate .1 to .3 gram gold on toast with vegemite, jam, or marmelade... Shocked

"The Double-D configuration is designed to significantly reduce ground interference and, thereby, recover the performance lost by a Mono coil over mineralized soil. With the Double-D, it is the arrangement of the TX and RX coils that produce a canceling effect of ground signals. This configuration is called DD because both TX and RX coils are in the shape of a ā€œDā€. The positive detection field of the DD runs beneath the overlapping center section from front-to-back. The remaining portion of the coil actually produces negative (i.e. canceling) detection fields. It is this canceling field that allows the DD coil to maintain performance over mineralized ground. Because of its small positive detection field, the DD is inherently less sensitive than a Mono searchcoil of the same size, over nonmineralized ground. The Double-D will, however, significantly outperform the Mono coil over mineralized ground. For this reason, it is highly recommended when hunting over mineralized ground commonly found when prospecting and relic hunting."

"The DD windings "see" aproximately 70% less ground effect than a Mono style winding and are quieter with smoother operation in areas where the ground matrix tends to shift. Also it is physically difficult to condense the electromagnetic energy into a narrow knife-like beam (directional field intensity) of a DD and achieve the same depth that a same sized Mono coil attains. A Mono provides the largest possible detection field and greatest detection depth, making the Mono coil potentially the most sensitive configuration available and will provide the best overall performance in most environments. Unfortunately, this configuration is the most susceptible to interference from ground minerals, which results in substantial loss of performance when used over heavily mineralized ground." Until the GPX's came along and changed the rules!

Mono's are deeper and more sensitive. Mono's see more ground and get more depth but can see more noise too as the most susceptible to interference from ground minerals. Using a DD is like turning down the sensitivity knob to run smoother-quieter so a person can hear better. If a Mono is getting about 20%+ more depth but you may not distinguish gold from ground noise. Yes DD's are a mute point(or mutted sensitivity), but sometimes they are needed, as you once recommended at least a round 16" DD or bigger for the type of ground around Kalgoorlie.

1) Ever met bad ground that a GPX 4000 or 4500 and Mono could not handle, and you HAD to resort to a DD?

2) In your armory what is your DD "go to" coil for bad ground that a Mono and a 4500 cannot handle?
Is it a round NF 18" or 20" SL DD or round Commander 18" DD or are your arms cheers as strong as tree trunks to handle swinging a round CoilTek 24" DD?

3) Does it work this way for the quietest to noisiest coils, the quietest coil is the smallest DD up to the largest DD, then the largest Mono down to the smallest Mono which is the noisiest coil?

Also both NF Advantage and CT GoldStalker are coming out with a brand new line of DD's soon I heard.


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Re: GPX4500....What is the maximum depth

Post  Guest on Wed Jul 15, 2009 7:14 pm

Narrawa wrote:
echidnadigger wrote:
Its obvious that there is a setting that doesn't make sense. Why?
Brett.
Do you understand now Brett?
Marco's settings would be better suited to looking for old axe heads & shovels.
Relic hunting perhaps.

Getting back on track with the thread topic, iv found many items at depth using the ML 11" mono, the last decent thing i dug was an old penny at Hill End the other weekend, it was 21" deep, no pics of the dig but Duckmaloi was watching.
Madtuna has also been sitting beside me whilst iv dug items at big depth with this set up in enhance.
ATM im to scared to go back to using my preferred coils, 17" NF elip & 16" NF round through fear of missing the goodies.
A question could be asked, what coil did ML base the 4500 on? was it the now supplied 11" mono as the 4500 appears to be more user friendly & mono orientated?
I with a lot of others are astonished at the depth & sensitivity that this combo can achieve.
yup....have been very impressed with the depth I've seen dug with the ML 11" mono by both yourself and Duck....in some crap ground too I might add.

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Re: GPX4500....What is the maximum depth

Post  nero_design on Wed Jul 15, 2009 7:50 pm

The new timings on the GPX-4500 were written with a monoloop coil in mind but there is nothing to suggest that they cannot and should not be used with Double-D coils. In fact, talking to a senior ML employee today in person and I spent this afternoon verifying that there's absolutely nothing wrong with using the DD coils in Enhance mode.

Narrawa, from what I understand, the 4500 was based on the application of the default 11" - with an expansion up to 16" Mono/DD. As JP pointed out, there's a conversation which he has with Bruce on disc #2 of his Seta Project which covers this. I see JP was hinting at using larger coils (in the video) with the 4500 but Bruce patted that suggestion back down to around 16" due to the inferred lack of stability and susceptibility to ground noise with larger coils being a known issue. There's no doubt you can use larger coils with the 4500 to fantastic effect but for absolute stability, coils above 16" might be a little prone to varying degrees of ground noise.

I'm not certain of development coils from NuggetFinder as they are very busy at the moment and can't keep up with demand for their coils right now. Coiltek are on the warpath with a range of DD Goldstalker coils which Trevor told me were due out around now. I've since heard there have been a few events which may slow down the release of these new coils. My American cousins have been testing the new DD coils and one forum poster contacted me to say that he was using an Elliptical DD from Coiltek and it was a very impressive coil giving up good gold.

/Waiting for the DDs... I'd like one for September to try in some place I've been saving ...for just this coil!
/JP's been testing out a new 12" NF Advantage coil (if memory serves me correct) and it's been giving him some great gold.
/The DD Goldstalker being tested by a North American appears to be a large Elliptical DD (22" or 24")
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Re: GPX4500....What is the maximum depth

Post  Beer Beeper on Wed Jul 15, 2009 8:26 pm

Thanks Marco, I think those new GoldStalker DD's are going to be open center and very lightweight. I wonder how a Round 24" DD compares to a large Elliptical 12x24" DD in performance and depth?? They both have the same blade down the middle, but a Round 24" DD has the wider size width. Does that give the Round 24" DD much more depth? Is the Elliptical 12x24" DD more sensitive? Does anyone know?

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Re: GPX4500....What is the maximum depth

Post  Jonathan Porter on Wed Jul 15, 2009 8:59 pm

nero_design wrote:Jonathan, it's been a while since I spoke to Bruce but that was a nice plug there for your 'Seta Project' DVD.... To be fair to you, I placed Disc #2 into the DVD player and note that at no point was there anything mentioned (by either you or Bruce) during the exchange as to the appropriate coil selection/choice for the Enhanced timing settings.
Then it must have been "The GPX factor" where Bruce recommends Fixed GB and Mono coils with Smooth mode.

The discussion referred in general to new timings and how the new detector was handling high mineralization.
The discussion in "The SETA Project" was referring to conductive (salty) ground being a problem for larger coils not mineralisation per se, you might need to watch that bit again!!

As I said before, it worked fine for me. This thread was about targets at depth with Enhance Mode active.
If this thread was about targets at depth using Enhance mode then I suggest your settings will not help in the matter.

BTW The 12" Nugget Finder coil I have been using and paid for is a Nugget Finder Advantage Monoloop.

Jonathan Porter


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Re: GPX4500....What is the maximum depth

Post  Jonathan Porter on Wed Jul 15, 2009 9:26 pm

Beer Beeper wrote:Jonathan P., yes you are right, big round Mono's are more profitable being maximum depth on larger gold as you said, BUT an elliptical Mono has maximum depth being much deeper on smaller fly **** gold, if that is someones bread and butter, ever ate .1 to .3 gram gold on toast with vegemite, jam, or marmelade... Shocked

G'day Beer Beeper, horses for courses mate, personally I prefer round coils over elliptical for outright depth on ANY target, the elliptical shape is far better for difficult terrain such as tight scrubby/brushy areas or when wanting to cover maximum area such as the 24x12 elliptical's made by Nugget Finder. I regularly find 0.1 gram pieces with the 18" Nugget Finder SL Advantage using Enhance.

Also it is physically difficult to condense the electromagnetic energy into a narrow knife-like beam (directional field intensity) of a DD and achieve the same depth that a same sized Mono coil attains.

I don't agree with this Beer Beeper, the blade pattern has nothing to do with the transmit field of a DD coil only the receive field and more specifically the way the receive manifests itself to produce the response on the coil surface.

......... making the Mono coil potentially the most sensitive configuration available and will provide the best overall performance in most environments.

Technically this is incorrect, a DD coil is actually more sensitive (actual size of coil compared to another of the same size) due to the smaller transmit and receive windings of a DD compared to a similar sized mono.


1) Ever met bad ground that a GPX 4000 or 4500 and Mono could not handle, and you HAD to resort to a DD?

2) In your armory what is your DD "go to" coil for bad ground that a Mono and a 4500 cannot handle?
Is it a round NF 18" or 20" SL DD or round Commander 18" DD or are your arms cheers as strong as tree trunks to handle swinging a round CoilTek 24" DD?

3) Does it work this way for the quietest to noisiest coils, the quietest coil is the smallest DD up to the largest DD, then the largest Mono down to the smallest Mono which is the noisiest coil?
Beer Beeper I NEVER use a DD coil or have never felt the need to since the release of the GPX-4000.
I do have DD coils which are, 20" Nugget Finder XP DD (plastic housing), 15" elliptical Commander, 11" Commander and 11" elliptical Commander.
The bigger coils tend to be less sensitive so therefore will run quieter in HOT ground except they are seeing more mineralisation so will re-act to different things to the smaller coils. The 11" Commander Mono is an excellent performer providing surprising depth for such a small coil on both small targets as well as large, to all new comers to the GPX-4500 I would highly recommend the 11" mono as a good supplement to the supplied 11" DD coil.

Hope this answers some of your questions,

Regards

JP


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Re: GPX4500....What is the maximum depth

Post  Ric on Wed Jul 15, 2009 10:44 pm

Claimpeg wrote:Has anyone found a target with the 4500 in Enhance mode deeper than 18 inches?

36" long Walco pick down this hole. enhance/16"mono.

Regards Ric

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Re: GPX4500....What is the maximum depth

Post  nero_design on Wed Jul 15, 2009 10:59 pm

Yes, I found that shield-nugget in the backside of a slab of rock that was essentially immersed in wet mud on the outskirt districts of Hill End. As I said. I picked off a lot of rock to get to it. The slab itself did NOT allow an approach from above due to the height of the main rock. Hence the pinpointer did the job.

People make the very same assertions about many of the nuggets you yourself have found although you probably won't have them say this to your face. And whilst I may not agree with everything you say, it doesn't mean I'm right either. It just means that we have had different experiences and opinions on the occasional matter. What I don't understand is why people are claiming "dumbness and falsehoods" when the subject here is about people's own experiences. And whether or not people have found TARGETS (not nuggets) at depth using the ENHANCE mode.

I say yes, I have. But I've also noted that in both cases there was a bullet cartridge there to act as a 'breadcrumb' of sorts... so perhaps my examples literally don't count in the end. I'll leave it for forum readers to make up their own minds. It happened.

* Hey Ric, that must have been a disappointing extraction! I bet you had some high hopes there before you unearthed it.
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Re: GPX4500....What is the maximum depth

Post  echidnadigger on Wed Jul 15, 2009 11:09 pm

Ric,
I know you will think there is some sort of innuendo behind my question (don't) but why is there no detector attached to the coil in the picture. Was a smaller coil used to pin point after the initial signal?
Brett.
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Re: GPX4500....What is the maximum depth

Post  echidnadigger on Wed Jul 15, 2009 11:15 pm

Just a thought,
If we could get Marco and Jonathan together to combine their skills, wouldn't we have one hell of an instructional video?
Smile guys its just a thought. Smile Smile
Brett.
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