The GPX 4000

This was the forerunner to the GP4500 and it obviously was a lot better than the previous models. Some of you are still using the 4000, so gives us your opinion and how to get the best out of the machine.

Views on the GPX4000

Jonathan Porter

Usually with the release of a new detector I am right up in the front line talking about what my experiences are and how the new technology will help us to make more good finds.

This time I decided to take a more restrained approach to see how things shape up with early reports from other prospectors experiences and if they concur with my own. Some people have really taken the bull by the horns and are achieving exactly what Minelab intended with the new technology, whereas others are still looking for the "conspiracy in the closet" failing to accept the reality, reading between the lines still others are fence sitting wating for more conrete proof the GPX is all that is claimed to be.

Outright depth aside lets focus on what the GPX4000 represents to us prospectors.
1st it is lighter, which is immediately obvious.
2nd there are less switches and knobs to choose from.
3rd there is an entirely new Lithium Ion battery system which weighs much less than the old SLA battery.
4th, the detector costs about the same as the previous model.
5th, due to the new digital interface you now have a plethora of options through the new menu system.
6th, inside the new menu system hides a whole new world of possiblities just the twirl of a control away, you want to control the gain? just scroll through and make your personal adjustments.
7th, you are new to detecting and aren't sure about what the detector is telling you? Try using the detector in the factory presets first untill you become more familiar with the controls.
8th, you hate being assailed by ground noise and pesky hotrocks and just want to focus on signals! The give the new SMOOTH timings a try using a monoloop coil. (7th and 8th are the same but from different perspectives)

If someone told me a few short years ago I would one day be able to go to the noisiest ground I could think of, and with a monoloop coil attached find gold I had missed with a DD coil, I would have laughed at them. Yet this is the very thing I have just done this morning.

Now before I relate my story I would like to point out that detecting is more to me than finding a fortune (although that does help when you do it for a living ), I love detecting for gold for its own sake and get a buzz out of a nugget no matter the size. I am realist enough to know that modern metal detectors expressly designed for the detection of gold nuggets are not perfect. But then again life isn't perfect either otherwise we would live forever (this could be a curse when you think about it ) which would then lead to a whole new bundle of issues like over population etc. In that vein I would also have to say, if there was a detector that could "find 'em all" then that would have to be very boring too.

I get a buzz out of heading back to an old favourite haunt with a new toy to see if I can squeek out another piece, and yes sometimes the reason a piece turns up at all is because of a return to the location with a fresh approach rather than the new technology. But who cares? it is fun and a good excuse to return, which is the whole point of the exersise.

I think Minelab have a difficult task here, because they have to try and please everybody. Some of us just want the performance regardless of the cost to the fly poo nuggets that lay in droves waiting to be discovered. Whereas others just want a smooth experience with no huge ground noise holes to make life difficult, where they can head on out for a few hours and have a better than even shot of finding something (no matter how small) to rattle in the container on the dash of the car on the drive home to show the family.

Well if you look at it that way, I think Minelab have done an excellent job. For us power hungry people we still have the GP3500 performance on deep gold, for the modernists we have a new digital interface and for the new chums we have a super quiet mode which will not confuse you with squeeks and #arts, with pops and wheezes and all the other general clatter of an electronic prospecting experience, NOISE, NOISE, NOISE!!!

This morning myself and friend decided to go for a bit of a beep around due to the weather cooling off the past few days. I had a spot in mind which I thought would produce the goods with the new SMOOTH timings of the GPX4000. I hope the GPX NEW CHUMS don't mind me muscling in on a new concept designed expressly for their use, because us professionals have discovered there is a decent living to be made on the enormous amount of fly poo nuggets laying around our old favourite haunts, so I have decided I want to be in on the action too.

Literally minutes into the session I was calling my mate over with his GP3500 to take a listen to a signal that could only be gold because of the depth and the packed wash the signal was laying in, sure enough it was a sluggy little half grammer, not exactly record breaking stuff but with todays gold price its worth 10 bucks which aint bad for a few minutes work . Just for the record my mates machine made a signal on the target too, but he had all the ground noise and hot rocks to contend with even though he was using a DD coil whereas I had a freakishly dead quiet machine even though I was using a Monoloop coil. After the session was over I had amassed 8 pieces for a tad over 6 grams, with my mate remaining goldless (admittedly he did spent a lot of time walking around with me enjoying the moment).

I am amazed on the new SMOOTH mode of the GPX, it seems the noiser the ground the better it performs. It is early days yet but I feel there are going to be some bigger pieces lurking in the deeper noisy ground too, but as we all know the bigger ones are easier to find (bigger signal therefore usually found much easier), however somewhere out there in the Australian bush is a patch or two where the new SMOOTH mode on the GPX4000 is going to come into its own.

Jonathan Porter

PS the biggest bit sounded like a 1 ouncer with an inverted signal response

....

In Australian gold field conditions, I know the ground in question intimately and have tested Minelab detectors there for over 7 years! The area I found my gold in today has been crossed chained many times with all the GP series machines and I can assure you has had a coil over it in all sorts of configurations and layouts. Why do you find it so hard to believe the GPX4000 might actually provide a real performance benefit? For the record the area in question is on my private property here in Clermont and as such I can assure all readers of this forum I am very well aquanted with the ground conditions, I can also assure everyone on this forum I am well versed in the techniques required for testing a new detector for any advantages over previous models.

In this case the GPX4000 is so far in front of the previous models it is embarrassing, this afternoon I went out to an area I filmed some of our first video on (look for a scene titled "Monoloop Hell" in the "Unleashing the GP Series") and managed to score myself 6 more nuggets in an hour and a half for a total of 14 grams for the day. This would have to be some of the easiest detecting I have done in a very long time (and fun too), the GPX purred along with barely a murmer, yet generated a positive "dig me" signal each and every time.

Yes I could have found gold with the GP3500 if I had put in the time, but I can assure you the mental effort would have been much greater and the reward far less.

I have included a pic of the gold I have been finding with my GPX for the unbelievers out there, I also stand by all my previous comments, the GPX is going to be a best seller for Minelab for the simple reason that it can be used in just about any ground type with minimal ground noise and minimal hot rocks. As a result I am currently targeting extreme ground with monoloop coils where I have had trouble detecting in the past even with DD coils. So far I have found 17 pieces for close on 20 grams in a little over 3 hours of detecting time all in ground I have pounded for years. Believe it or not folks this detector is as good as it sounds in the noisy ground types.

I don't really care about all the dramas that have been going on since the release of the GPX4000, because at the end of the day it is the gold you are finding that counts and more specifically if you are finding it in haunts you have been to a lot in the past.

An ounce of GPX gold for a total of 6 hours detecting!!

This morning was just plain fun as I start to get a grasp on what the GPX is capable of. My favourite coil so far has been a Nugget Finder 16" Super Light Mono, they are light and more importantly don't sound off when bumped (this does not mean others do BTW ) which is vitally important if you want to become proficient with the new SMOOTH timings of the GPX.

This mornings effort, 14 Grams of the good stuff!!

The best bit of advice I can give with these new timings is to swing low and slow (just like a DD actually) and pay attention to any repeatable type signal response because the chances are very high even the faint little whispers will be a good target. Usually I will do a quick GB off to one side and then check the target zone again, if the target persists then DIG!

The day was starting to heat up, but it was worth it!!

It is also vital you do not detect in Auto GB at all, or else you WILL Ground Balance out targets. The other thing you need to keep in mind, even though the coil sounds balanced you still need to hold the Fast Trak button down and carefully pump the coil for at least 5 seconds before releasing the button. You will not be able to hear an awfull lot as this function is being performed (unloess the GB is completely out) but believe me it is important, as some ground noise can break through if the GB is not correctly done.

Check out that blood red ground, thats why the gold is still there!!

This morning I found 8 pieces of gold for close on 14 grams which takes my total since returning home to 34 grams. The second last signal for the day was in a small channel run off, which are notorious for concentrating heavy minerals that have washed down from the higher slopes, normally even a DD struggles in these areas. Not so with the SMOOTH mode and a Mono coil on the GPX. The initial response was a very confused signal (high/low-Low/high all jumbled up), but the signal sounded so sweet I had to dig, when I hit packed gravels 3 or 4 inches down I knew I was on a winner but was still chuffed when a 17 gram speci literally dripping with gold came to surface a few minutes later.

JP

Fossils Views

By way of introduction my nick-name is Fossil. I have had it since I was 12 years old. Some people used to laugh when they heard it, but these days they don't. Therein lies a story. I have been gold prospecting and relic searching for 25 years. Metal Detecting is my hobby, sport, and leisure time and occupies a large part of my life. I make a living desiging and manufacturing prospecting equipment and also sell metal detectors and accessories, including ML products.

I can hear some people howling at this stage. Can I be trusted to give a balanced view of the GPX4000? If you think not, read no futher. My loyalties lie with my customers and detecting friends, not with any brand or company. Performance is paramount to me. If I like something, you might hear about it. If I don't like something you WILL hear about it. If any company comes out with a better detector, I will be the first in line for one.
I was offered a chance to trial the 4000 about 5 weeks before its release. Why me? I think ML was looking for a "New Technology Challenged Older Fart" with some knowledge of detecting, to see if I could drive the new format in gold detecting. I AM NOT A FIELD TESTER FOR MINELAB! That work had been done by JP and others.
My first attempt on heavy mineralised ground was ordinary to say the least. I thought I knew it all but this detector is different. Okay, when all else fails read the manual. I had pushed the 4000 beyond the limits for that patch of ground. After an hour or so I thought I had it under control, but at that stage there was no obvious advantage over my 3500. In the past I used mainly DD coils on medium to heavy mineralised ground in Victoria's Golden Triangle. I was not really interested in sensitive mode with mono coils because of ground noise and loss of depth on some targets.

I was asked to provide some hot rocks for testing so I set the 4000 in sensitive and the new smooth mode with a 16" mono. Any rock that gave a signal in that mode should do. I went to a popular flogged hot patch of ground I had trouble with for many years, to find the hot rocks, but was surprised to find 3 small nuggets before I found a hot rock. I used sensitive and smooth mode on the next few outings with surprising results. I went from patch to patch, area to area on many Victorian goldfields to try the 4000 on as many different types of hot ground as possible. The nuggets and many other targets kept comming from these heavy mineralised flogged areas, but nothing over 6 grams. I taped my 3500 control box to the 4000 control box and had to use 2 battery packs and leads. I kept out of sightwhich was hard to do at times, I had to make a few quick exits. If anyone saw me, it would have looked an odd sight. My arm nearly fell off some days.
When I found a target or possible target with the 4000, I did not dig it, but searched the area and marked other targets or possibles. I then changed the coil to the 3500 and checked the signals and possibles. I tried many different settings on both machines to get the best results from each. Some of the targets were gold, most were junk, and a few were hot rocks, clay domes and charcoal. All of these targets were missed by me and a multitude of others.
Using the 16" mono, the 4000 was very stable in threshold which made it easier to hear the faint but clear signals, and about 60% of the signals and possibles with the 3500 were lost in the ground noises. I prefer this method of testing, but it takes a long time.

I am cautious of set-up test patches. They ARE necessary to test new machines, and if done correctly, provide good results if the "UNDISTURBED GROUND" method is used. I have seen a few releases of new detectors over the years using this method, but they are still open to shady practices. Anyone who has attended these releases, and were a wake-up to what was going on, know exactly what I mean.
Just after the release of the SD2000 I organised a demo for a group of interested prospectors on a heavy mineralised area. I arrived 10 minutes before the group, and set up 7 target areas. When the group arrived one bloke produced a detector he was pushing. I showed him the 7 target areas, and to everyones surprise, and with some regular adjusting of his detector, he found all 7 targets. The problem was, only 3 of the test areas contained a metal target. The 2000 got the 3 easily. END OF STORY
DON'T BE FOOLED, THE EASY GOLD IS GONE FROM MOST POPULAR GOLDFIELDS. You have to earn it now. I had one of the first SD2000's released. What a great time it was, but with 10 years of better detectors and better operators, they have depleted the available gold nuggets. NOT REALLY. Since the release of the 4000, a small group of detector friends and I have been visiting only flogged, heavy mineralised areas with very pleasing results. Now I am more familiar with the 4000 I make fine adjustments and can get even better results.
I am cautious about saying the best settings to use, because it varies from one area to another. I feel that if 10 prospectors from 10 different areas were to give their best settings on the 4000, they would most likely all be different, and all would be correct. We now have a simple pre-set detector, or a multiple setting drivers machine all in one. I have heard of some tests on the 4000 on larger nuggets on a heavy mineralised test patch. The results were a bit ordinary I am told these guys know what they are about. I do not doubt their results on their test patch. My test area was as many of the heavy mineralised areas in the Golden Triangle as I could visit in approx. 8 weeks. All of these areas have been a problem for 25 years. The depth of the 4000 and small and larger targets in these areas was nothing short of impressive. All the targets I found were still there because of 1 reason. They had been missed by earlier detectors and operators.
One small hot patch I've had gridded 6 or 7 times in the last 2 years, yielded another 21 nuggets, for 3.5 ozs. Don't get me wrong, these machines find gold, they don't make it. If it's not under the coil, and not in range, END OF STORY.

On one trip, guess who left the crowbar and post hole shovel at home. I dug a thin "u" shaped brass item, about 3x2" x 1/4" wide, from 2'10" deep on the edge of a bladed big nugget patch. Kev dug a thin corroded piece of brass 2.5"x1.5" at 2'6". My target was early in the day and took me 1.5 hours to dig. It nearly wrecked me for the rest of the day. 30 meters away I got a similar signal which took 20 minutes to dig, and at the depth of my 16" mono on edge, a 54 gram solid nugget appeared. Other nuggets for the day:- 1 x 15.5 gram at 16", 1 x 10 grams at 15", 1 x 8 grams at 13", and 16 smaller nuggets from 3 grams to 0.5 grams at impressive depths. All with a 16" mono coil, from a heavy mineralised flogged area.
Last weekend was Bob's first walk with a 4000. He had been chasing Barramundi in WA since the 4000 was released. We all felt sorry for him. I set it up in sensitive and smooth mode and other settings to suit the area. Misery Gully had been just that for the last 20 years for us. A bad, variable mineralised area. After 1 hour and a few junk targets he dug a 38.7 gram shaggy piece at a measured 18" deep. Our picks have inches and feet marked on the handles. I got 19 pieces for 20 grams.

My Conclusions:- The 4000 needed a back light. It needs a full length fibreglass shft, especially on larger coils. The 4000 loves mono coils in hot ground, any ground for that matter. It has improved depth in heavy mineralised areas if driven right. It has a smoother threshold. When conditions permit, you can crank up the gain. If a "new technology challenged older fart" like me can drive one, anyone can.
I realise that by writing this article, I will be targeted by some. So be it. The amount of gold I found with the 4000 says it all. To me, the 4000 is a different animal. Drive it wrong and it might bite you. Drive it right and it will be your best friend. This is my opinion of the 4000 and I am happy to share my experiences. My aim is to provide some positive and constructive comments on the 4000. You make up your own mind. Two 4000 owners, one a very successful WA professional, the other is Roger, the guy who found the 51oz "Golden Goose", both said the 4000 is the best improvement in detecting technology since the SD2000. I stand by their comments. This is a one off article. Sorry to be long winded.
I hope to see some of you in the bush one day. We can have a cuppa and a chat. Hang on just a minute. If you have a 4000, NICK OFF. Go and find another spot.


Tim the Toolmans Views

Great forum post by Fossil and I agree with him and also most of the other posts out there including Martins.....It seems some just won't accept that technology continues to leap forward, sometimes at lightning speed. The gold is still there because the older machines have missed it.......Some will say " the operator " was to blame, yes in SOME cases it may have been BUT can you blame the 100's of operators that have all hammered the same ground since the early 80's.....GET realistic and admit that the gold is there because the older machines could not run Mono's SUCESSFULLY over the same ground as what the 4000 is currently doing....

I called into to Heathcote on Friday arvo, very hot and dry and was shown some spots to try that have produced a fair bit of gold. Bottom line was a very RED gravel reef chop that has provided several forum members a lot of gold over the years. This gravel was very noisey and the 4000 with a Mono coil on the settings I was using was driving me nuts. I turned the gain from 12 back to 8 and also changed the swing speed from slow back to very slow and BINGO this machine was running deadly quite, smooth and stable once again. I was rewarded instantly with a very slight hum that turned out to be a very skanky dirty 1/2 grammer down around 8 inches that was simply missed by the DD's......My first Heathcote piece of gold after several unsucessfull trips.....

So at the end of the day, all that people are providing is first hand feedback to those who are thinking of the upgrade, for those who continue to knock.....GAL, continue with whatever machine you are using and allow those who wish and can afford the upgrade some peace and quite from your broken record whinging

Should I upgrade?
The gold that would have been missed by the other machine "IS THE ONLY FACTOR THAT PAYS FOR YOUR NEW MACHINE" not every nugget you find with it.
cj