It's been 12 months

[Jonathan Porter]

Hello All,

I would first like to add, I will not tolerate any attacks or negative comments about AZO on this forum. Chris is not only my cousin, but a long time nugget hunting partner of mine.

All I ask is to keep it clean and talk about anything related to prospecting for gold.

With that said, I've had great success here in Arizona with my Minelab GPX-4000. With this metal detector I can fine tune to just about any ground condition with a monoloop searchcoil.

I've found a couple hundred nuggets with mine so far, which is more than some and a lot less than others.

Wishing you all the best,

Rob Allison

Hello Rob, sorry for the negativity on your forum. I understand your feelings about kin, after all blood is thicker than water! To that end you have gone way up in my estimations of a man who stands by his convictions. I have had a few good conversations with DOC recently, he has informed me you are that sort of person.

Rob you are well known in Australia as being a very determined prospector, there are only a handful of Minelab dealers world wide who actually practice what they preach. If you ever want to come to OZ for a bash at the Outback, let me know.

JP

[Carson Steve]

Thank you for the clarification, Bob.

[Lamar]

Dear group;

Wow, what did I miss??? Why JP doesn't post on AZO any more? Isn't the Pacific ocean, plus California, a wide enough space between Arizona and Australia without having to create even bigger rifts between people? Some peoples' kids, I tell ya.

And yes, Rob Allison is well known as a dedicated, devoted and determined detectorist the world wide. When I got started detecting, I posted some questions on an Aussie forum and I was referred to Rob. This was on an AUSTRALIAN forum, mind you. Best advice I ever got too.

Now, everyone leave JP alone. Mind you, it's fun to get him all spooled up every now and again, but when people stop posting on various forums due to anger or other negative emotions, then it starts becoming real and this is one thing nobody needs in their lives.

Personally I am glad to see JP posting here on Robs' forum and I hope he continues to do so.

Your friend;

LAMAR

[montana]

JP. You are right about me not liking any chatter of the threshold. While I was still running the 3500 I stated that it was a wonderful detector , but would not be upgrading if there were not great strides made in eliminating EM interference. I got an inkling that there had been improvements along these lines when the first info started coming out of Australia (via JP ) . I was one of the first ones on the list for a GPX4000. Dumbing the detector down was not the way I thought I was going to go, but I found that with the increased ability to crank up the settings, I also was back to square one with an interference problem. Dumbing it down started showing promising results as I got the threshold smoother and smoother. Surprisingly it had the effect of my getting ever smaller and deeper gold because it was easier to hear them without the chatter. My thoughts went back to the VLFs where increasing the gain would start to diminish returns beyond a certain point because of increased ground noise . The faint signal was there but masked by other noises. I've found my comfort zone with the GPX which may not be the same for everyone , but the ability to find your comfort zone exists with the GPX like no other PI detector in the past.-----Bob

[DigAU]

JP, glad to see your are still posting on this hemisphere. There are only a few who post about the GPX 4000 settings and you and Montana seem to be willing to share. I don’t post much but do read and try to remember what you guys post. I was wondering if you or Montana found a setting that reduces wind interference?? I haven’t had any other detector than the 4000, but find that it will detect gold (and lots of other stuff) as deep as I am willing to dig. Thanks for sharing.

Terry

[Lamar]

Dear DigAU;

The reason why JP and Montana are the only two willing to share their knowledge about the settings on the GPX-4000 is because they are most likely the only two people in the entire world who have been able to figure out how the detector works! That thing has more knobs, buttons and switches on it than I care to mess with

Your sticking with the 2100 friend;

LAMAR

[JW.]

Even though I have yet to actually find the gold I really like the GPX. I came to electronic prospecting from turf hunting with the Explorer 2. I'm finding the GPX to be a monster of a machine and without your dvd I would have been months back still at this point.

I read the post that you linked and I would argue... ,not really, that he isn't 'dumbing down' the machine, he is making subtle adjustments to a machine with lots of available power. Fine tuning has net him gold at worked out patches and really the fine tuning ability is why I purchased the GPX over the 2200.

Sometimes I am bummed that my GPX doesn't get the really small specks and in trashy spots I wish I had tone ID but each time out I am amazed by the ability of the detector. I made a small test nugget that I use to tune the machine so i'm not tuning out small gold.

When hunting close to power lines (within 1/2 mile) running boost is out of the question but typically I can get the threshold mellow so I can hear the small/deep target sounds.

I'm pretty happy but would be happier with some yellow in my pouch!

JW

[Jonathan Porter]

Carson Steve. Most people think that by running a mono in DD on the control box, a little better sensitvity is achieved.......

Montana, I don't think sensitivity is the right word, it has more to do with the way the electronics are behaving when in Mono mode compared to DD. Remember Mono mode trys to convert a coil to a psuedo Monoloop, so to my mind this will be confusing to the detector when a single wire coil is attached. I have found a GP/GPX is more stable in extreme mineralisation and has potentially more depth (in the low percentage points of performance difference). However Mono mode does provide some benefits due to a smoothing out of the threshold which only Deep mode can provide in any of the other settings (Deep mode is not liked by a lot of users and is probably not a good choice in high EM areas).

I should also point out you can back off the gain quite a bit when selecting deep mode and still have a lot of performance (this is the Deep mode option in the menu not the front end cap switch section, which has a lot of changes ot other settings when useing factory presets). Deep really does lift the signal on nuggets from 5 grams and up especially if they are down a bit.

Even though I have yet to actually find the gold I really like the GPX. I came to electronic prospecting from turf hunting with the Explorer 2. I'm finding the GPX to be a monster of a machine and without your dvd I would have been months back still at this point.

I read the post that you linked and I would argue... ,not really, that he isn't 'dumbing down' the machine, he is making subtle adjustments to a machine with lots of available power. Fine tuning has net him gold at worked out patches and really the fine tuning ability is why I purchased the GPX over the 2200.

JW

JW I also agree with you that dumbing down is the wrong description for what Montana is doing, he is fine tuning his machine to suit the conditions and as such has been immensly succesful, not only that but has also helped others be more successful thanks to his willingness to share . If a detector as powerful as the GPX can find gold we would have been very proud of when we used VLF machines, you could not in all conscience describe the settings used as "Dumbed down" . I am open to suggestions on a new naming convention for Bobs methods, something that is more in line with what he has achieved.

JP

[grubstake]

How about saying I maxed out the detectors potental, for my area. Grubstake

[Miner Matt]

JP It looks like to me were this machine really shines is in the smooth mode and haveing the ability to set your track speed.

Looks like this would be a good platform to work off of in building the next Minelab?

I would love to see a machine that would discriminate out small iron(boot tacks, wire).

Take care,Matt

[Steve Herschbach]

Hi JP,

I'm sorry about all the negative stuff here. I have tremendous respect for you and have found your posts to be great sources of information. So I'm glad you are posting here and hope you continue to do so.

Been using my GPX all summer. I'm nowhere near an expert with it but have found about a pound of gold with it. I'm easily more pleased with it than any previous Minelab and look forward to learning more about the machine. The one thing they can add for me in the future would be to give back the control over channel one and channel two and the option to use manual ground balance.

On my own claims at Moore Creek the Smooth mode has been a real winner but I also like the ability to crank up the Gain in our low mineral areas near Anchorage. More control, that is what I like.

Steve Herschbach

[MrSandsman]

Well Hello again JP I have followed your posts way back. To the comment about why the settings in OZ and the setting in AZ differ, I would just like to say detecting is a hobby that you have to use all the information you gather over a period of time and the more you can understand your machine in all different kinds of ground minerilization the better detectorist you will become. JP's experiance in the field with numerous different detctors birings one hell of a learning experience to the table I for one am gald to see you post and I dont even have a GPX 4000 I have a GP3500 but you can be sure I will pick some good info out of this post to use with it

Happy Hunting

HotRock

[montana]

JP . I'd love to use deep on the audio, but our interference has a profound effect on what audio setting we use and reducing the gain does little to improve the situation. I doubt that you would use it much if you were doing all your detecting over here unless you have a high tolerance for a wobbly threshold. I'm sure there are some folks who use the deep audio and are willing to accept the instability and they are welcome to all the nuggets I've left behind by not using deep (if they can hear them through the chatter). There will never be agreement on settings for the GPX as long as there is a difference in ground from one place to another and different levels of interference from one place to another. Northern Nevada has a lot less EM interference and deep would probably work fine up there, but here in central Az. Commercial aircraft , military aircraft, and General aviation craft are like a swarm of bees overhead at all times with all radar electronics going full blast to keep them from running into each other, along with the ground radar , there are probably no worse places on earth for EM interference. Australian detectorists would have no concept of this situation.

JW . What do you mean your GPX won't get the really small specks? I've got plenty of specks less than a grain with mine. How small do you want them?----Bob

[Jonathan Porter]

JP, glad to see your are still posting on this hemisphere. There are only a few who post about the GPX 4000 settings and you and Montana seem to be willing to share. I don’t post much but do read and try to remember what you guys post. I was wondering if you or Montana found a setting that reduces wind interference?? I haven’t had any other detector than the 4000, but find that it will detect gold (and lots of other stuff) as deep as I am willing to dig. Thanks for sharing.

Terry

Not sure what you mean by wind interference Terry, could you perhaps go into a little more detail? I have instances where interference has been driven downwind from power lines, perhaps this is what you mean.

JP

Hi JP,

I'm sorry about all the negative stuff here. I have tremendous respect for you and have found your posts to be great sources of information. So I'm glad you are posting here and hope you continue to do so.

Been using my GPX all summer. I'm nowhere near an expert with it but have found about a pound of gold with it. I'm easily more pleased with it than any previous Minelab and look forward to learning more about the machine. The one thing they can add for me in the future would be to give back the control over channel one and channel two and the option to use manual ground balance.

On my own claims at Moore Creek the Smooth mode has been a real winner but I also like the ability to crank up the Gain in our low mineral areas near Anchorage. More control, that is what I like.

Steve Herschbach

Hello Steve, thanks for the recommendation with the film group from the US (Mercedes), they contacted me about filming here in OZ and might end up doing a segment on my property here in Clermont around the same time they do some filming looking for Sapphires.

Glad to read you have been having success with your GPX 4000, a pound of gold (1/2 a kilo) not bad considering you have been running an exploration program and also a tour venture as well as your other business (yes I do read a lot of your posts on the web, especially the stuff on Moore Creek).

You can essentially get similar control to the 2 channel functions of the SD series machines with your GPX by selecting either Salt mode (mimics channel 1) and Sensitive Xtra which is probably more sensitive than the old channel 2 option of the SD's. Due to the dual voltage tech in the GP series machines the ground signal is not as pronounced hence the greater sensitivity to smaller gold in extreme mineralisation, Minelab have now taken that a step further by digitising the back end of the GP platform which opens up a plethora of opportunities via adjustments and filters etc all neatly contained within a simple to navigate menu structure rather than switches and knobs strung all over the place.

JP

PS thanks to all the posters of this thread for keeping it clean, part of me would love to create a fuss because of what I feel has been a great injustice, but as one of your greatest ever presidents once said "It would just be ashes in our mouths". I have far more to lose by stepping down into the gutter; that loss would be your respect, so with that thought in mind I humbly thank you.

[FlakMagnet]

JP,

Regarding Terry's wind interference comment, I can say that I also

notice that the wind affects the sensitivity of the GPX.

It is more wind-prone than the 3500 I owned previously.

This is experienced as a warbling in the threshold that gets more unstable

as the wind rises...it is especially noticable in gusts.

I have sort of put this off to the increased

sensitivity of the GPX and the (uninformed), opinion that perhaps the wind

generates a subtle EM interference of it's own, but it really upsets the detector.

I would be interested to hear people's thoughts on this too...

If you hunt in the desert, eventually you will be hunting in the wind.

Flak

[sdf527]

Question Re: EM Interference

Experts: I find that my 4000 is very sensitive to dried desert grasses. What I mean by that is when sweeping the coil over the sparse dried weeds and grasses, I get a variety of warbles and artifact noise. Generally, after sweeping several times over the same patch the noise dissipates. It really wears down the concentration though.

What kind of settings do you recommend to keep these noises to a minimum and not lose too much sensitivity?

JP and Montana - Thanks for opening the classroom for us.

Stephen

[JW.]

JW . What do you mean your GPX won't get the really small specks? I've got plenty of specks less than a grain with mine. How small do you want them?----Bob

Under a grain...! Wow, I can just hear a .3 gram with a 8" ML mono coil (I hear this coil isn't very good) right on the coil's surface... I'm planning to get the small NF 5x10 mono, which should get me some more sensitivity... I hope...

I'm going to have to review some of your posts Bob and see how you have the machine set-up...

Great posts folks, nice thread JP!!

JW

[Jonathan Porter]

OK without actually being there I would have to say that the interference being experienced during windy days is from the wind pushing the interference from hi voltage power lines. I would love to hear from prospectors who are experiencing this to get back to us here on the subject, let us know what you are experiencing and if there are any power lines within a 1 miles radius. Actually if this subject continues with a lot of people coming back then it might be a good idea to start a new thread about it to keep eveything in the one place.

JW said....

Under a grain...! Wow, I can just hear a .3 gram with a 8" ML mono coil (I hear this coil isn't very good) right on the coil's surface...

JW the Minelab Commander coils are purpose built for the GPX machines, and the 8" round would have to be one of the best coils of all time (I think it is one of Bob Dansies all time favourites). The only problem with the larger Commanders is the weight factor because they are built like a sherman tank, I used the 15 x 12 Commander in the GPX Factor DVD and found it to be superb when coupled up with a HipStick.

sdf said....

I find that my 4000 is very sensitive to dried desert grasses. What I mean by that is when sweeping the coil over the sparse dried weeds and grasses, I get a variety of warbles and artifact noise. Generally, after sweeping several times over the same patch the noise dissipates. It really wears down the concentration though.

Firslty Stephen, not so much of the expert because an X is an unknown quantity and a spirt is a DRIP under pressure, although I was described in those unflattering terms not too long ago, so maybe you are right!!

A couple of questions, firstly what coil are you using when this happens and secondly your settings if you don't mind? If you run too high a gain any sort of response in the threshold is going to stand out (not suggesting you are BTW Stephen), you would be surprised what is hidden from view down in that low drone. I have suffered from some of your problem when using large mono coils in Smooth mode, this does not surprise me because Smooth can be slightly problematic when used in conjunction with a large mono (18" plus). But the real reason is, because the vast majority of ground signal has been removed you can now hear all the nuances in the threshold that would normally be masked through constant threshold feedback from the detector reacting to the ground. This feeback BTW is something you don't even realise is there until you go to Smooth and find how quiet things are.

Montana wrote....

I'd love to use deep on the audio, but our interference has a profound effect on what audio setting we use and reducing the gain does little to improve the situation. I doubt that you would use it much if you were doing all your detecting over here unless you have a high tolerance for a wobbly threshold. I'm sure there are some folks who use the deep audio and are willing to accept the instability and they are welcome to all the nuggets I've left behind by not using deep (if they can hear them through the chatter).

There will never be agreement on settings for the GPX as long as there is a difference in ground from one place to another and different levels of interference from one place to another. Northern Nevada has a lot less EM interference and deep would probably work fine up there, but here in central Az. Commercial aircraft , military aircraft, and General aviation craft are like a swarm of bees overhead at all times with all radar electronics going full blast to keep them from running into each other, along with the ground radar , there are probably no worse places on earth for EM interference. Australian detectorists would have no concept of this situation.

Bob I have used Deep a heck of a lot all over the place (in fact I tend to have it on permanently) and do not even notice the moaning sound other prospectors complain about when using the mode, so I have obviously trained my mind to ignore something that others find irritating. Your areas sound very challenging, I remember when we were filming the NHE videos out at Bumblebee the unit would just ramping up into an incessant mindless chatter and seconds later stabilise again, I remember commenting at the time about "how the heck do you deal with that" As far as I'm concerned if someone can deal with that and be successful then I for one am going to sit up and pay attention, especially if your are finding nuggets in the grains size. I sincerely hope someone from Minelab reads these forums and is taking note for future concepts.

JP

[JW.]

I got a Hip Stick a few months ago, talk about a nice addition to a prospector's tool belt!!! Worth it's weight in gold and it is cheap too!!!

I swing one of the green 18" mono coils every once in a while, without the HipStick I could feel the iso rod assembly bend under the weight, no fun on the hills either, whole other story with the Stick!

Guess I was misinformed about the ML 8"...

[nuggethunting]

Hello JW,

You should be able to find a 2-3 grain nugget easy with the GPX-4000 and the Minelab 8-inch round mono. The Coiltek Joey 10x5, Minelab 8-inch Round and the NF 10x5 are all great coils for small gold. I've found them as small as 0.7 - 0.8 grains with these coils.

Keep in mind, your hearing, headphones and settings can't cause you to find or miss these small gold nuggets.

Take care,

Rob Allison

Hello All,

Forgot to mention what i wanted to say about interference. I've found you will encounter EM Interference when you're around Overhead Transmission or Distribution Power Lines, Airplanes, Hydro-Dams & Windy days. These are some of the more major ones I've experienced here in Arizona.

Take care,

Rob Allison

[Jonathan Porter]

Rob Allison

Hello All,

Forgot to mention what i wanted to say about interference. I've found you will encounter EM Interference when you're around Overhead Transmission or Distribution Power Lines, Airplanes, Hydro-Dams & Windy days. These are some of the more major ones I've experienced here in Arizona.

Take care,

Rob Allison

Hello Rob, sounds to me like you have just described most of the US, I tip my hat to you guys the worst we have to contend with in OZ is mostly thunder storm activity. There are a few areas around the country were urban build up is encroaching on gold nugget spots (Victorias golden triangle, some areas in New South Wales and places like Gladstone here in QLD plus a couple of places around Clermont) but nowhere near as bad as what you have to contend with. The problem is when you experience more than 2 sets of interference at once which is what I think Bob Dansie is talking about, especially in your Monsoon season .

As an aside, Minelab have designed each and every GPX 4000 to be individual in its operating frequency, so if you have a number of GPX users hanging out together the cross talk should be a heck of a lot less than other Minelab PI's.

JP

[JW.]

Keep in mind, your hearing, headphones and settings can't cause you to find or miss these small gold nuggets.

.1-.2 Grains? There is no way your using Smooth, can't be (WTF do I know anyways..)... But I can see why I have yet to hear such a thing, where I hunt, within a half mile of a power station along a river my threshold is never really steady so picking up that little speck through the constant fluctuation has been tough to down right impossible...

But I will say, IF this machine can get that small then I feel way better about my investment, thoughts of using my Explorer were creeping up and I was beginning to wonder if the GPX was for big gold only! And if so why not have tone ID and just use my turf machine, except I did dish out some $$ for the GPX so I have stuck with it even though i'm not finding the gold... I'll have to do some more experimentation when i'm a little further away from electrical interference to see if I can get that little nugget I have for testing......

I did notice when I used a probe I could find many more hot rocks and small bits of metal without the smooth setting switched on... Lots of targets in the creek, black hot rocks from the lava caps everywhere, I was going nuts in normal settings, got lazy and switched to smooth...

Thanks for the info guys!

HH

JW

[nuggethunting]

Hello JW,

I'm not sure who said .1 - .2 grains ... I have personally found hundreds of nuggets that are in the range of 2-5 grains with no problems on all the GP and GPX detectors. I've found them under a grain, on the surface of the bedrock with the Coiltek Joey Mono & GPX-4000 combo in the Sensitive/Smooth mode and Quiet audio. When I'm hunting very small gold, I prefer Sensitive/Smooth & Boost, or Sensitive/Extra & Boost for dinks.

Hope this helps a bit,

Rob Allison

[Jonathan Porter]

Actually Smooth mode will give much better performance on small nuggets in high mineralisation compared to other settings using mono coils, this is due to two things. One is the almost total removal of the ground signal and the other is highlighting of those targets in the signal/threshold that have always been there due to a mono's inherent sensitivity over a DD coil but is masked due to the aforementioned ground signal. Surprisingly Smooth mode has also been productive in areas I would have considered to be quiet in the past so it is interesting just how much mineralisation the Minelab detector ignores even in their most sensitive state.

Robs suggestion of using boost is a good idea so long as you have a day where the interference is low. I rather increase the Motion settings first before selecting boost, however each option has its merits, a careful use of both can produce surprising results.

JP

[JW.]

Sorry, my bad on the weights... I'm not used to grains yet...

Rob, thanks for the suggestion on the modes, even though I can't set my machine up perfectly yet I love the fact that it has the ability and i'm not feeling handicapped by the machine.

For example; I hunted an old camp in the Sierras with my Explorer and the hot rocks were giving me fits, the machine was not setup to handle or tune that stuff out, made it a huge issue to hunt, not to mention a headache at the end of the day.

Looks like i'm going to have to revisit JP's bundle of dvd goodness again, they are full of great information and tips, not to mention the finds...

Big thanks fellas!

JW