ProspectingOz

[Reg]

Hi Steve,

Years ago, Fisher came out with a fancy design called the double derivative and boy did it sound great. The problem was, the fancy double derivative simply meant two filter. Now, calling it by its more common name sort of does let the air out of the sails, doesn't it?

The fancy terms are not the tricks involved that help ML's. I have looked at enough of their schematics to see that there is no "magic" involved. Yes, Candy is very intelligent, but as another very well known design engineer known for his work on VLF's once told me, much of what he says even in his patents is old news and taken from other sources.

A guy by the name of Corbyn patented a ground canceling PI in 1981 that really has some benefits to it that may improve what we have today. Without trying it, it is hard to say.

If you look carefully at the latest ML series of PI's, the latest doesn't blow the doors off any of the previous models, especially on larger gold. It simply has improvements to find smaller gold and appears to have reduced some of the EM problems.

Don't get me wrong, the ML's are very good PI's, but they still have their problems, just like all other detectors. At present, there is no doubt, they are still king of the hill.

Now, as for Whites and the GS 5 blowing the doors off the ML's. Well, that isn't going to happen simply because even the ML is about at the max depth wise given the fundamental design. The simple improvements on the smaller gold is a no brainer. Simply sample sooner. That is why my GS 5 can blow the doors off the 4000 when it comes to detecting invisible gold.

As for sheer depth, that is why people still brag about their older SD's. Even the older ones will compete the latest and greatest on the bigger stuff, depth wise. The advantage of the latest design is they have been trying to reduce the "noise" and, of course, do better on smaller gold. The trick now is to simply refine the present design and get the most out of this design and that is what ML is doing with the latest and is what will be in the next model.

So, why does the ML appear to go so much deeper than some other PI's such as the GS 5. Actually, the answer lies more in the techniques used in audio design than in PI design. Candy figured out how to use lower noise IC's such as the AD797. He also used "textbook" techniques in his filtering as well as his preamp circuit. the original GS 5 design is and was a good decent design with respectable depth. However, with a few changes to the preamp, alter the sampling a little, and refine the filters and filtering speeds and the GS 5 is a whole new detector.

When first looking into ways of improving the initial GS 5, Eric found out several things about his "established" design for a front end. What has worked for years, had its own problems when trying to sample sooner. This lead to a better design in that area. Other well established designs that have evolved over the years, evolved as a matter of reducing parts, rather than other reasons. Since the modifications didn't show any negative effects, they were considered improvements. Now fast forward and begin to look for the best techniques to improve the sensitivity and some of the key areas of limitations began to surface.

So, the major complaint regarding the difference in depth capability of the GS 5 and the ML's has really been a good thing in the long run. Hopefully, much of what has been learned even over the last year will begin to show up in newer designs. . In other words, simply don't stuck in the same frame of mind used on previous designs and you gain that extra depth found on other detectors without the need for DVT or XYZ, etc. As a simple example, I recently changed just 4 matching parts and gained around 3" in depth of detection on a 1 gram nugget when compared the abilities of the original GS 5. Figuring out just why and what 4 parts was the hard part.

So, the big question is, can anyone make a detector that competes depth wise on the typical size of gold we find here with the ML and doesn't step on their patents? My opinion is yes.

Now, we have to see just what Whites starts out with.

Reg

[nuggethunting]

Hello Reg,

No, never tried or considered selling used cars. I would rather stick with something I know and support. Unfortunately it's not US made.

Would you recommend me selling the GPX-4000 and trying something else out? Do you think I could be just as successful?

Talk with you soon,

Rob Allison

[Steve Herschbach]

Hi Rob,

Of course you'll only use the best! But I know you sell an SD2100 now and then...

Reg, I sure like reading your posts. And I hope you are right. All Rob and I and a lot of end users see is Minelab owning the market for over 15 years now and others struggling just to get in the ballpark, let alone equal Minelab top end performance. So whatever ever Candy is doing has held the high ground for a long time. How he is doing it could well just be magic as far as I'm concerned. I know guys like you claim there is something called electricity going through wires and something called magnetism. But old as I am when I see a magnet pick up a piece of metal, well, it still seems a bit like magic to me. And the minute I first used a metal detector it was magic - I can see stuff underground!!!

Yup, it is all magic, and guys like you are the wizards. So get back to work on that magic wand!

Steve Herschbach

[Reg]

Hi Steve,

You are right, ML has held the high ground for a long time. Unfortunately, none of the US manufacturers were willing to step up to the plate until now. What people have to remember is ML has been at this PI thing for, what did you say, 15 years now. So, they do have a head start. I suspect the Whites will be an improvement over the GS 5 but will not be the perfect detector everyone would like to see.

So, do I see the Whites to be the savior right out of the box? Of course not. I don't know exactly what they are doing or what mods they will implement. They have elected to be totally closed door and that is their business.

Lets hope they do well in their initial design.

Hi Rob,

You really need to read your post then read mine and then think very carefully about what you said and then note that it was coming from a ML dealer. Steve is right, even you sell one of the SD's once in a while, but the way you phrase things such as "lesser detector" even has to apply to all previous or other ML's based upon your statements as well as other PI's. I personally won't call any working PI a lesser detector, but that is me.

In answer to your question, do I think you could find almost the same amount of gold using a different detector, my answer is yes. You have done it with all previous ML models and surprisingly , they were the "best" at the time and all previous models were now the "lesser" detectors. If you were to take the SD 2100 V2 out tomorrow and hunt with the intensity you do with the 4000 you would find gold. The reason is simple, you are good with a detector.

Is there an edge towards finding smaller gold with the 4000? Does it have other features that make it stand out? Again, the answer is yes. But are all the differences worth an extra $2000 over the cost of a low end SD to the person who may only hunt a couple times a year and is on a tight budget? Not in my book it isn't. Are the added features worth it to the guy who hunts gold for a living or has the money to toss around, the answer is yes.

Now, I never even mentioned you should sell your 4000 and try something else. If you can afford it and enjoy the hobby as much as you do, then the logical choice is the 4000. So, I didn't even come close to stating anything like you should try something else. I just tried to point out in my own blunt way what you sound like when you jump up on your soapbox and "rant" about the 4000 the way you do. I know you are enthusiastic about the 4000 but you have been just as enthusiastic about all previous models of MLs and now, they are all part of the "lesser group you mentioned. There are a lot of people who can only afford the "lesser" detector or maybe only want to pay what the lesser detector sells for. Should they not buy one?

The cold hard facts are these; even the lower priced SD's do extremely well and will find gold; not everyone can afford the new 4000; not everyone wants to spend as much as a 4000 costs; nobody has ever questioned your ability or desire to use what you feel is the best or suggested you use anything else; not everyone wants to lug a heavyweight like the SD or 4000 around; and there are people who own other PI's such as the Infinium that just love them. Many have been quite successful also.

Is the 4000 generally better than anything actively being produced by a competitor at this time, the answer is yes. No one has even implied otherwise that I know of. Is the 4000 perfect? Of course not. If it was, there wouldn't be a 4500 or 5000 or whatever ML wants to call the next model waiting on the side lines. Now, is the 4000 worth twice as much as the SD 2100? Not to me it isn't and it isn't to a lot of other people. To keep this all in perspective, I don't buy Cadillacs or Lincolns either. Personally, I prefer the lesser cars. I will buy what is practical for me and I strongly suspect that is what most people will do.

Oh yeah, when is ML going to get their act together and be able to detect the invisible gold my GS 5 can detect? Do we have to wait until the 6000 model? By then, I will have a fully working iron ID feature on mine and ML will have to play catch up again.

Reg

[seeker]

A lot of good points being brought out and as most of us are just end users and not techs I think some of the features the 4000 has that I really like are control over the sweep speeds and the push button GB to keep the electronics tweaked up anytime the user has the ability to make fine adjustments will push the performance of the unit towards the Max rather then just click positions and hope for the best. Another thing coil technology has improved also to the point where larger ones are not necessarily arm benders but liteweight performers the coils do run smoother with the adjustibility of the unit...Thanx guys for your insights and this thread, Arctic Hysteria has me in its deadly grip, hope someone posts up some gold soon.......Good Hunting Geo...

[Reg]

Hi Seeker,

I am assuming when you refer to controlling the sweep speed, you mean how the detector responds and not how fast you can swing the coil.

Will you expand on that feature a little? I am going to guess that the response from targets changes from a slower weeeeee/woooooo to a faster wee/woo when you change sweep speed adjustment. Please let me know if this is sort of what you mean or if I am way off base.

Thanks,

Reg

[nuggethunting]

Hello Reg,

When I refer to "lesser PI's" I'm referring to price vs. Minelab's.

I probably would find gold just as much with an SD with my experience, but I know I wouldn't get the depth on smaller gold and find the small stuff I can find now with the GPX. I'm still not convinced the SD is going just as deep on larger targets where I hunt. I've done some testing of my own on my ground conditions and I've seen slightly better depth with the GPX.

I don't put any faith in what another detector (including Minelab's) can do in another country. I hunt 99% of the time in Arizona, so I put faith in those tests more than any others.

Talk with you later,

Rob Allison

[seeker]

Hi Reg this is one area I have not really been able to experiment with much as most of the hunting I have been doing amounts to poking around small brushy areas so I'm using basically a 14" elliptical coil or the smaller 8" Minelab. I haven't had a chance to use the patch setting with the faster sweep speed selection with a larger coil on..As I understand it with the faster speeds you get rapid target response and a sharp clear signal. My guess would be you would need to take your gain settings and signal balence into consideration also, but the adjustments are there to be able to take advantage of varying possibilites with the end user making corrections as the matrix changes...Geo

[Ridge Runner]

Steve

I spent 35 years in electronic's pushing voice and data through copper wire but then they change the game with fiber. That's the way technology is it never stops for anyone it's always changing. I think the detector companys can't afford to make change on a new detector they just put out.They have to re-coop their money plus make a profit before putting a new model out.Two factors come into play with everyone and that is what I can afford and again what I can afford.Those two will add up to what I will buy be it Whites are Minelab.

Reg

If I had half the smarts you got running around in your head I'd go get a GS5B take it apart and make it so hot people couldn't get within 15 feet without getting a dose of radiation.All of this is because I'd like to be hunting with the best detector on the market but again that little word what can I afford.

Rob

I don't think you need to get a dealership for White's just yet.I want to see more on how it affects the price of Minelab than out doing it.

Hold everything I just got a call from WHITE'S saying the new PI will have high speed muffler bearings and I told them that's good being Minelab don't.

If you see me with both detectors will the reason is Minelab has a quite exhaust. What can I say just like women I love them all. I know now I must be dreaming.

Chuck Anders

[Jonathan Porter]

If you want small Gold just get an old SD2000, up the clock frequency, increase the filter gain and it will out detect a 4000 with ease. I found that the GS5B would find Gold the ML machines missed if the ground was extremely hot. ML only developed the smooth mode in order to compete with the quietness of the GS5B.

I am also hearing good things about the Whites machine, should be a very serious competitor to ML, especially in Australia.

Woody that is an utter load of rubbish and just goes to show how wives tales and innuendo can flourish on the net. I know how the Smooth mode came about because I was there and was instrumental in its development. Just for the record I have never laid eyes on a GS5B except for poor Fred Masons at Rich Hill when I was last in the States and it wasn't even switched on.

JP

[Reg]

Hi Chuck,

The rumors are the new ML is more of a software change than a physical hardware change. In such cases, if they can jump the price up a couple of hundred bucks for another light or bell, why not? So, I won't be surprised if ML does come out with something new especially if the Pulse Devil makes it over there shortly.

Now, changing the subject to me basically taking the GS 5 apart and making "hot", I have already done that and put it back together hotter than it ever was. In fact, I just figured out it was so hot my last trip to AZ that it affected my 4wd and I had to get it fixed. So, I have to be more careful next time since I can't afford to have to fix my vehicle each time out.

Actually, for me it is the fun of making the mods and seeing something work better that drives me. This type of play keeps the cobwebs from forming, and at my age, I need all the help I can get.

So, regardless of what new detector comes out, I will always be modifying and changing things. The problem is, once something is almost done, it points out something else that just may require a major mod going in a different direction, so it never ends.

It is just like my iron ID feature. Now, on my low powered PI, my present ID design works excellent. It is very close on the higher powered ones like the GS 5 also. But right in the middle of it all, I figured out a new way of doing things so now I needed to try something else, which I think will work better. So, as always, it is back to the drawing board.

However, what complicates things is during this "off time" when I really can't go nugget hunting, it is more like vacation time and I just can't seem to get started with mods. I know I really need to get started, but somehow I manage to avoid it.

It happens like this every year, so it isn't something new. It is just extending longer the older I get. Also, once I know I have to design a new pc board, things just stop since I really hate doing that.

On a different note, I am somewhat like you when it comes to buying a new detector. It is a matter of buying what I can afford, or more of what I am willing to pay for. At times I wish I would have purchased a GS 5 when they first come out because I would have started then with the mods. As it was, I couldn't justify the expense since I only go nugget hunting a couple times a year and what I was using still fit my needs. So, it was later that I obtained a used one.

This last year or so has been the best, though because to make the detector distinctively better has required a lot of thinking outside of the box. I think part of my drive has been because Whites purchased the rights to the GS 5. So, if I could come up with changes that enhanced the GS 5, they would most likely make their way to the new PI or at least to the company. Personally, I want to see the Whites become a success. We need all the American jobs we can get.

The irony is, it hasn't taken that much to enhance the GS 5 quite a bit. This is why I know the latest version of the GS 5 is much better than the first since I share my findings with Eric. Somehow, he can always find a technique to enhance what I have done, so between the two of us, some really interesting things have been done.

Now, I am nowhere near the genius he is, but I can take the detector out away from noise and test it, which is something he can't do easily since we still have a lot of open space out west. There is very little of that in England, so he is always at a disadvantage because of the electrical noise he has to deal with. It is absolutely amazing just what shows up when there is no noise masking things. Many of my best ideas have come during such times.

One more advantage is I have no time constraints nor do I have to meet any expectations, so I am free to modify and do as I please. As such, my initial ideas are quite helter skelter. Companies such as Whites generally do not let their engineers do the same. they set time lines and limits. Can you imagine an engineer coming up with an idea similar to my present iron ID and then when he was almost finished coming up with what he felt would work better and then going back to the "boss" to tell him we need to stop go a different direction and by the way, it will only set production back a few months? Right, that isn't going to happen.

The problem with designing anything new is to recognize something is possible and then find a way to make it happen. What most people do not realize is during the "make it happen" stage, just how many other new ideas can crop up if you are watching carefully. In any design one should look at it objectively and try to find any weakness even if it is your own design. That is the hardest part to do. I think some of this has been happening at Whites and that is why there have been some delays. Again, that is just my opinion.

Reg

[woody]

It is sad when I have owned just about every M/L detector from the GoldSeeekers 15000 to the modern units. It must say something when I have ditched all of the M/L detectors but stick with their first offering P.I the SD2000. In my view each new model of M/L detector was a step backwards, especialy on deep targets.

Just by increasing the clock rate and other small mods I can detect small Gold like a 4000 but I can detect all Gold deeper than any later offerings. To have the best Gold detector on the market all one needs to do is find an old SD2000, change the preamp IC reset the bias point, change the output fets for lower rds on, change the source resistors, change the damper resistance, increase the gain in the integrators and the filters, add low and high frequency crystals to cater for small or large deep Gold, run the thing on 8 volts or more if you want to modify the internal switchmode supply to handle it. There you go , an all round detector that shits on every other offering to date.

[pennyweight]

Hi Woody, when you say the modded 2000 can acheive huge results on small gold, have you tested the unit on harsh mineralisation? What is the threshold noise like? My GPM modded 2000 was hot on small gold but noisy as hell in lots of areas. Sort of defeated the purpose on a few occasions! Found me sh*tloads of yella metal though! I know what you mean also re your previous post about the GS5b. Word is that the Minelab Marketing board wanted the next unit (GPX4000) to have all the same features. Not knocking the sensitive smooth timings though, it just rushed Mr Candy in releasing more innovation sooner. Shows what real competition in the marketplace can acheive! Cheers, Dwt

It is sad when I have owned just about every M/L detector from the GoldSeeekers 15000 to the modern units. It must say something when I have ditched all of the M/L detectors but stick with their first offering P.I the SD2000. In my view each new model of M/L detector was a step backwards, especialy on deep targets.

Just by increasing the clock rate and other small mods I can detect small Gold like a 4000 but I can detect all Gold deeper than any later offerings. To have the best Gold detector on the market all one needs to do is find an old SD2000, change the preamp IC reset the bias point, change the output fets for lower rds on, change the source resistors, change the damper resistance, increase the gain in the integrators and the filters, add low and high frequency crystals to cater for small or large deep Gold, run the thing on 8 volts or more if you want to modify the internal switchmode supply to handle it. There you go , an all round detector that shits on every other offering to date.

[nuggethunting]

Hello Woody,

Thanks for the information on the SD2000 mod. However, for most, they will never do it, nor do they know how. Many would probably end up screwing something up and then be out of a metal detector. For the guys that are very tech savy like yourself, then it might be worth modding a unit with all the stuff you mentioned.

Take care,

Rob Allison

[woody]

Hi Guy's

This forum is read by a lot of manufacturers as I have found out by getting a couple of emails and phone calls. Maybe I could send the Mod details to Reg and he could Mod the SD2000 for the U.S users.

Apart from that I may have a mod for the 3000/4000 series that gets rid of all (most) electrical interference, just need some control boxes to mod and get some field data back. Maybe Reg can do this in the U.S?

DWT, Just think that if M/L kept the SD2000 timings and married that with the 4000 integrator set up what a detector we would have

[Jonathan Porter]

It is sad when I have owned just about every M/L detector from the GoldSeeekers 15000 to the modern units. It must say something when I have ditched all of the M/L detectors but stick with their first offering P.I the SD2000. In my view each new model of M/L detector was a step backwards, especialy on deep targets.

Just by increasing the clock rate and other small mods I can detect small Gold like a 4000 but I can detect all Gold deeper than any later offerings. To have the best Gold detector on the market all one needs to do is find an old SD2000, change the preamp IC reset the bias point, change the output fets for lower rds on, change the source resistors, change the damper resistance, increase the gain in the integrators and the filters, add low and high frequency crystals to cater for small or large deep Gold, run the thing on 8 volts or more if you want to modify the internal switchmode supply to handle it. There you go , an all round detector that shits on every other offering to date.

Woody all that tells us is the SD2000 is the only PI machine Minelab have ever made that you can tinker with the rest have EPROM's, tinker with that and you have a DEAD detector! Instead why the heck don't you make your own detector, even if it encroaches on Minelab's Patents that's only if you want to market them, personal use shouldn't be a problem .

JP

[woody]

The code that is used on the 3000 series has already been modified by a couple of techs in Australia, Did you hear that M/L contacted a certain person who is developing a new detector in order to buy out the project?

[Reg]

Hi Woody,

Thanks for the confidence in me, but I don't have time to even do the things I should now. Someone else will have to do the mods on the ML's over here.

BTW, did you ever find a really good way of removing the white paint? Someone had asked that question on another forum.

Reg

[nuggethunting]

Hello Woody and Reg,

I know AZNuggetBob was interested in that also. Could you tell us why Minelab used the colored paint on the circuit boards? Why would someone want to remove the paint, to see what Minelab has done or reverse engineer what Minelab has done?

Talk with you soon,

Rob Allison

[Reg]

Hi Rob,

ML probably added the paint to slow down the reverse engineering.

Enough people have already copied the design (reversed engineered) so that is a non issue. The reason for wanting to know the easy way to remove the junk is if I wanted to replace a component, or if someone else like Bob did, what would be the best technique to use to remove the crap. Some people may just want to try the SD 2000 mod. Knowing the best way to remove the paint or whatever the stuff is just makes life easier.

Just for the record, there is no magic involved. It is well engineered in many aspects, but, in my opinion, sort of sucks in others, which probably explains the greater problems with external EM noise than other PI's. The important thing is the design works very well most of the time. It just doesn't like EM of any sort.

BTW, a ML (or any other PI for that matter) isn't my stepchild so I don't have to defend it. I just look at the design, the benefits and the limitations objectively like I try to do all designs. Unfortunately, when I do this to a ML, it causes ML lovers to get upset. Jeez, it is just a detector and not your step kid and you just found out he had to wear glasses.

If you missed the glasses part, many years ago I really did work with a guy who was very upset because his son had to wear glasses. This meant, at least to him, his kid wasn't perfect.

Reg

[AZNuggetBob]

Hey guys I'm not trying to build a super detector and take over the world market. I understand why Minelab ground off processor markings and painted there boards? It was to protect their technology, rightfully so. I'm only interested in doing my own repairs and at the most probably upgrade my 2100 to a newer version of what Minelab already has available. The only difference is I like working on them and its a little cheaper than buying a new one. Minelab has consistently upgraded their detectors with every new one. And what I mean by upgrading is along with circuitry and the newest technology changes (improvements) they also make them more user friendly.Their not selling the same detector year after year. If you think their a little over priced just try buying some of the parts for repair they used to build them. Granted the parts on their older detectors are a little out dated now but at the time they were original built they were some of the best high quality parts available. That is the way it is with electronics. As a matter of fact you could build a 2000 now with modern day parts of the same values Minelab used in 1995 and have superior detector than an original 2000 out of the box only because the parts are better now. I have no doubt that Minelab could push their current detectors to a higher level, but they would be giving up user friendliness and stability and that may fly with some of us pro's but not with the general public. Enough said. AzNuggetBob