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Ran across this video of a Whites TDI in action... Seems the threshold is very unstable. Question to you guys using this detector is that normal or can that be smoothed out? I am used to the smooth and stable GPX threshold and all that noise would make it difficult hearing faint targets I think not to mention drive me batty.

He gets a nice little nugget with it.

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Hi Bill...I used a friends last year...so this would be one of the first made...it did have a ragged threshold but still was great for hunting silver/copper coins in an old park...I didn't get to use it nugget hunting...

I believe the newer models and the Oz Pro version have been improved in that regard...if I were buying a new TDI I would insist on the Oz version as I understand it is different than the USA version...

Fred

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Hi Bill

I have one and the tone is smooth as glass.White's let dealers sale the TDI only if they take a class on it but if not your not going be selling them.

It's like Minelab your better off if you have had field training with someone that knows the detector than not.

Chuck Anders

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Yes, Bill. On the earlier models the threshold will get ratty if you use too much gain. Just like on a VLF machine, you use as much gain as the ground will allow. Too much and it gets erratic. With practice and experience, the pros can use it with more gain and still pick out the weaker signals. A beginner would have problems. I don't know how experienced this guy was, but it was his first time out with it and may not have had it set up right.

On the TDI, a gain of 6, or half way, is all you need. Bumping it up to 12 does not make much difference in the target response but can make a big difference in the threshold. But still, it has been one of my own sticking points about the machine. It should be stabler at max gain. The newer models, especially the TDI Pro, have reduced that but not eliminated it. And, of course, other factors come in to play; ground, EMT, etc.

Digger Bob

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Howdy Everyone... I'm on slow dialup and a slower typer... I have one of the first "hole" TDI's #13 off the line. I bought in late 2007 as a reconditioned machine through White's of California.

From the "get-go" I used Digger Bob's recommended settings. (Thank You Digger Bob!). However, I kept the sensitivity at slightly less than half way... It has been absolutely stable with Bob's settings in the Randsburg/El Paso range of Southern California. All I use is the standard 12- inch "dual" circular open spoke "Mono." :)

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Howdy Everyone... I'm on slow dialup and a slower typer... I have one of the first "hole" TDI's #13 off the line. I bought in late 2007 as a reconditioned machine through White's of California.

From the "get-go" I used Digger Bob's recommended settings. (Thank You Digger Bob!). However, I kept the sensitivity at slightly less than half way... It has been absolutely stable with Bob's settings in the Randsburg/El Paso range of Southern California. All I use is the standard 12- inch "dual" circular open spoke "Mono." :)

Hi Jim,

Thanks for your input my friend and hope all is well on your end...

Cheers, Bill

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Bill... Thank you. I really appreciate your support over the years. While I'm here, one correction to make in my last post. It was about December 2008 (not 2009) when I bought my TDI.

One thing I will add about my early TDI... as we know electrical and magnetic fields are present wherever electricity flows. I found my TDI to work great around some California Distribution and Transmission (power) lines.

However, it is my understanding the Distribution lines can vary from one to 80 milligauss under the line and Transmission lines can vary from one to 300 milligauss at the edge of right-of-way.

My point is that some Pulse detectors (No matter brand) can work under power lines. There are a lot of "high-lines" in southern california as an example cutting through the Mojave and Great Basin deserts in Southern California and elsewhere.

(Even some VLF- type detector can flounder under the (EMF) electical and magnetic fields that are generated by power lines...)

I have asked BLM leadership about powerlines on BLM managed

ground... as there is an easement... if the the ground is open to BLM management or the easememt tqkes precident; as the powerline sure doesn't want someone digging deep holes while drywashing (as an example). I got no asnwer; but decided to let sleeping dogs lay... I have detected under the lines while there were untility workers in the area and they did not pay attention to me... ???

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Hi Jim,

Yes sir and using earlier PI detectors was a nightmare (again all brands) under power lines except for a early Eric Foster Goldscan (I think) modded by Reg Sniff I saw demonstrated by Reg many moons ago, he was able to make it purr under high tension lines where my SD 2100 would not hear the same small nugget he tested with.

My old Gold Bug 2 also worked under the power lines well.

Now though the GPX series will work and from what I hear TDI will work also under or near power lines if adjusted properly with a DD coil. Sometimes the mono is usable also with the GPX depending on load in lines....

Re-adapting one's strategy as things change and areas are more worked allowing more difficult areas to be worked still pays as it did years ago. Still much more enjoy the challenge of finding that next unmolested patch.

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Bill... You are right about Reg and his modded Goldscan. As you know Eric Foster designs are the heart of the TDI.... My early "hole" TDI works well under the powerlines and I have been able to recover several

"pennyweight" shallow eluvial nuggets with it.

I go out with others, such as Sandtrap Jerry Balcer who has a 4000 and Jeff Myers who has a Minelab 3000. I was with Jeff who was able use his 3000 under high tention lines which highly impressed me as I tried to hunt there back with my 2200d just before I sold it to Grubstake (and I might add it worked better for him then it did for me :thumbsupanim ).

I will agree that great strides are being made in both Pulse and VLF technology. As gold becomes more ellusive, technology with bring the needed tools to recover paystreaks and patches still overlooked.

You are absolutely correct that we need to adapt our strategy to finding new areas to hunt... they are out there but it will take both/either dumb luck or research to find them. It is too easy to walk over gold while looking for gold...

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Hi Jim,

Yes I know about the Goldscan and tested the new version of the Goldscan 5 for Eric Foster and Bill Crabtree about a year before it was announced White's was buying it. It was a good PI, but still had stability problems at that time. Glad to hear White's has dialed it is better as stability is always the key to more finds...

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Hi Jim,

Yes I know about the Goldscan and tested the new version of the Goldscan 5 for Eric Foster and Bill Crabtree about a year before it was announced White's was buying it. It was a good PI, but still had stability problems at that time. Glad to hear White's has dialed it is better as stability is always the key to more finds...

Come on Bill I was with you one time when you were testing the GS--I found a nugget with my extreme and had it out of the hole and that GS did'nt even peep over it--- stability was not an issue-shortly after that you went and got your ML and used it the rest of the day--Remember that :inocent: -Mike C...:ph34r2:

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Come on Bill I was with you one time when you were testing the GS--I found a nugget with my extreme and had it out of the hole and that GS did'nt even peep over it--- stability was not an issue-shortly after that you went and got your ML and used it the rest of the day--Remember that :inocent: -Mike C...:ph34r2:

Yes I do as a matter of fact, if I remember I had to really mess with the settings to settle it down which really cut the sensitivity to targets. I did not hunt with it that day :inocent:

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Bill and Mike C... Thanks for jogging my memory. The earlier Goldscans did not have a ground balance mode.

About the Extreme, I was with Rick Di Bacco who still has it. We did a little detecting around the power lines a few years ago and as I best remember after he re-tuned he needed to set the RX switch down to cancel and re-tune to quieten the interference. And as I mentioned earlier, Jeff Myers was able to (recently) run his 3000 under the same power line with no problem that I'm aware of.

But then again, I have found out that being able to work under a hi-line can be "iffy." Some days you can and another day you can't; while under the same line. Gosh I guess this is all I know, so I will now be quiet. :twocents:

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Jim,

The Early Goldscans did have a ground balance control including the GS 5. Certain other PI's made by Eric did not have that control, one of which, was the Goldquest.

Mike C.

I wasn't there when you observed the lack of detection of a nugget that was out of the hole, but that was quite possible if the delay was adjusted. Certain larger coils required a delay adjustment to work correctly. It didn't take much of an adjustment to ignore a small nugget. Outside of that, I am not sure why the detector couldn't detect the nugget. Without being there, I suspect that was the situation, since I never heard of a malfunction of any of the initial units. I have one of those now and it works fine. In fact, I tweaked it just a little and it can detect smaller gold that most PI's including the SD's and most GP's. Before the tweak, it could at least match them for detecting the smaller stuff.

What the GS 5 wouldn't do was go as deep simply because it didn't have the sensitivity built in. Because there wasn't as dramatic of a sensitivity amplification, the GS 5 never did display any of the odd EM problems. That is why this detector could be used directly under power lines, and never suffered from noise from jets or airplanes.

The earliest Goldscan 5's really needed an increase in sensitivity, which was done quite soon after the initial ones were made. That was a simple mod.

The later GS 5's and the TDI's have been designed to minimize the requirement of adjusting the delay when trying to use larger coils. It still could be possible on the largest coils made to work on the ML's.

Today, my TDI is super quiet, especially when in the single tone mode. The extra quietness adds several inches to the detection of the smaller stuff. My GS 5's have been modified to do the same.

Keep in mind that none of the above mentioned detectors can match my low powered PI to detect super small gold. I can get a nice strong signal from a couple of "invisible nuggets" that, when last checked with at least three 4500's didn't produce a peep. My TDI will detect those invisible nuggets but not as well as my low powered one.

Reg

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Howdy Reg... thanks for keeping Straight "straight." You are the "MAN." I sure need and welcome all of the help I can get. As you know I lucked out when I bought a referbished TDI from White's. I did not know it would be an early "hole" machine.

All of the information on the Goldscans, Goldquests, TDI, and the various Minelab PI's take us back to one of Bill Southern's earlier posts... "Re-adapting one's strategy as things change and areas are more worked allowing more difficult areas to be worked still pays as it did years ago... " Best to all... jim straight

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Jim,

The Early Goldscans did have a ground balance control including the GS 5. Certain other PI's made by Eric did not have that control, one of which, was the Goldquest.

Mike C.

I wasn't there when you observed the lack of detection of a nugget that was out of the hole, but that was quite possible if the delay was adjusted. Certain larger coils required a delay adjustment to work correctly. It didn't take much of an adjustment to ignore a small nugget. Outside of that, I am not sure why the detector couldn't detect the nugget. Without being there, I suspect that was the situation, since I never heard of a malfunction of any of the initial units. I have one of those now and it works fine. In fact, I tweaked it just a little and it can detect smaller gold that most PI's including the SD's and most GP's. Before the tweak, it could at least match them for detecting the smaller stuff.

What the GS 5 wouldn't do was go as deep simply because it didn't have the sensitivity built in. Because there wasn't as dramatic of a sensitivity amplification, the GS 5 never did display any of the odd EM problems. That is why this detector could be used directly under power lines, and never suffered from noise from jets or airplanes.

The earliest Goldscan 5's really needed an increase in sensitivity, which was done quite soon after the initial ones were made. That was a simple mod.

The later GS 5's and the TDI's have been designed to minimize the requirement of adjusting the delay when trying to use larger coils. It still could be possible on the largest coils made to work on the ML's.

Today, my TDI is super quiet, especially when in the single tone mode. The extra quietness adds several inches to the detection of the smaller stuff. My GS 5's have been modified to do the same.

Keep in mind that none of the above mentioned detectors can match my low powered PI to detect super small gold. I can get a nice strong signal from a couple of "invisible nuggets" that, when last checked with at least three 4500's didn't produce a peep. My TDI will detect those invisible nuggets but not as well as my low powered one.

Reg

Hi Reg good to see your still around and as always your knowledge of the PI inner workings and Vlf's far surpass anyones here so with that said I'm all ears :hmmmmm: as far as the situation where Bill could'nt get a peep out of that nugget with the GS proto type if could of very well been operator error :shhhhh: what kind of depth do you get on small gold with your low powered PI and when you say small gold--how small-would it be possible to incorperate the high powered and low powered units into one-just curious---Thanks Mike C...:ph34r2:

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Hi Mike,

My low powered PI can find the invisible nuggets with ease. A one grain nugget is an ear blaster if the detector is set up right. The key is the ability to reduce the delay sufficiently that even extremely small gold generates a reasonable signal. That can happen at a delay of well below the magical 10 usec range.

The short delay allows for a much stronger signal so what happens is the low powered unit can actually produce signals on small gold better than some of the high powered PI's. A few years ago, I found an 8 grain nugget on one of the pushes that has been beat to death for several days prior to me getting there. Why was I able to find it while others failed. Easy, the nugget had dropped into a slight pocket and no regular size coil could get close enough to it to produce a signal.

I was using a rather strange coil, about a foot in length but only 3 inches in width. The odd design allowed me to get close enough that I got a great response. Later a guy came up and asked if he could test his 3500 on the small nugget. So, we basically compared the two machines, my low powered unit and his 3500 to see what difference there might be in detection depth on this particular nugget. The result was I could detect the nugget as deep as he could. To be honest, there really wasn't any difference depth wise that I could see.

Now, as the nugget size would get smaller, I have no doubt my low powered PI would begin to show a depth improvement. On the other side of the coin, on larger gold in the size approaching a 1/4 oz or more, the higher powered PI would clearly detect the gold deeper. But for gold in the gram or two size or less, the low powered PI really would shine. In fact, it would run with some of the better VLF's without the problems from black sand.

The reason was simple, the low powered PI would allow sampling well below the 10 usec range but above the range where black sand would generate a signal.

Could one incorporate both a high power and a low power into a PI? Yep, it could be done. The best way would be to switch more than the power level, which means changing FET's for the best result. The key to a low powered PI is the power level is down, which is obvious in the name. What isn't obvious in the name is when using low power one can use a different FET which can allow for a faster response on the delay signal. This allows for sampling at a sooner rate.

Right now, I know of a particular low powered PI that recently had some unique changes made that further enhanced the design. This new detector is now super quiet which effectively allows for deeper detection yet. I am hoping Whites elects to buy the design and bring out a PI aimed at finding the small gold. This, in my opinion would be a very smart move since they could capture a unique market that really should be targeted, in my opinion. So, we will see.

Reg

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Thanks Reg,

Your input on these subjects is always welcome...

After some adjustments/changes were made to the unit I was testing it worked much better and better handled the hot soils I was asked to do my testing in. Bill Crabtree trained me on how to use the GS5 and I did also have a manual. We used both Minelab and NuggetFinder coils as well as the stock GS5 coil with Bill C. being present for the first testing phase, then I was sent a different control box again because of ground stability issues. Once we would get it adjusted to run stable we lost much sensitivity, but we were testing for the first time in AZ in some very hot ground for this very reason and Eric would tweak as needed after discussion with Bill C.... We also had some issues with pulse delay adjustment at first.

I think I had a Minelab Commander on it with Mike or perhaps the stock one, but not sure as it is a long time ago. Very well could have been coil or operator error as I was new to the GS5. I was still impressed with many aspects of this PI and I said to Eric and Bill that it was a very good entry level PI in my opinion if the stability issues were solved which seems to now have been done. Like I said after the unit was worked on the only real thing I had to mess with was keeping the ground stable here in AZ and at that time it worked best with the stock GS5 coil.

Now White's has made some changes and the TDI is an excellent PI and does a good job in the field from reports I have heard from actual users. I have not used the White's TDI as yet, but know where I can borrow one and may have to check it out a little more closely. I was somewhat out of the loop for a bit and usually like to test new detectors before mouthing off about them so I will remain silent for now on the TDI and how I think it compares to other brands or where I feel it stands in the pecking order. There is currently a gap in the market and White's seems to be filling it quite nicely...

For us that hunt gold as a second job type hobby so to speak it is simply a numbers game and having more actual coverage options including coil sizes are my main interest. More Depth x coverage in a stable threshold = more nuggets. I will always use what gives me this advantage no matter the brand on the box. Currently the Minelab GPX 5000 is filling that slot for me personally quite nicely.

Best of luck with the production of your low power PI sounds exciting and hope it happens! A PI designed for targeting small gold at depth would appeal to many I am sure.

Cheers, Bill

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Hi Bill,

The low powered PI isn't mine, but Eric's. He added some tricks that makes it quite the detector that has very respectable depth.

Now, the original GS 5 went through a few adjustments before it stabilized. Part of the reason is Eric has to test his detector in a very congested area so it shines when compared to the competition, which can't handle a lot of em noise. That was part of the problem since the TDI had such an advantage in really noisy areas that setting the initial sensitivity was done incorrectly.

A couple of changes later and the GS 5 worked much better, but still wouldn't compete depth wise with the higher priced ML's in areas with little interference. In such areas, the ML reigned supreme. That is still the case today especially on certain size gold.

Instead, the TDI has the unique feature of being able to target specific objects based upon the conductivity of the object. This allows the TDI to be able to be used in places such as the middle of Octave and still target certain gold.

The ground balance/disc feature reduces the depth capabilities, so one sacrifices depth for selectivity of targets.

Yesterday, I found a nice nugget weighing over a half oz but found it with a GM4/B I had just worked on the day before. I was simply testing it to see how it was working and trying the iron ID function when right in the middle of a bunch of trash I got a good signal that turned out to be the nugget.

Had I been using a straight PI I probably would have walked away from that area since there was a nail every couple of feet. Later, I checked the area again using the TDI but set the detector to detect that nugget I had just found but still ignore nails. So, I could basically search the same area and still know when to ignore most junk. That could be done using the low conductor mode set up to ignore nails. Since that nugget was very large for the area, the odds of missing anything because of running the TDI in the low conductor mode was really quite remote since this larger nugget responded like a low conductor target. In other words, once I knew more about the gold in the area, I could simply set the detector accordingly. Only certain small pieces of tin cans or other very thin iron junk would give me much of a problem and even then, I could tell most of that junk.

The point being the TDI can't go head to head for depth with the higher priced ML's but it has its nitch because of the hidden features of the detector. Turn off the GB and the depth of the TDI approaches that of the higher priced ML's. Now, that was mentioned on another forum and dismissed because it can't be done realistically, at least according to someone who knows nothing about the TDI. In fact, there are a lot of places where the GB can be turned off or at least turned down to almost nothing and the detector will purr right along with minimal problems from ground signals.

The TDI isn't perfect, but it is functional and works well, especially if one takes time to fully understand the controls and how to adjust them to take advantage of the detector's capabilities. One shouldn't expect a detector that costs about 1/3 as much as the king of the hill to go head to head. To think that or try to make that comparison is ridiculous. The fact of the matter, it was never intended to go head to head but to be used where its advantages become obvious.

Since I don't get to go nugget hunting much, it simply isn't practical for me to dump a lot of money into a detector I can't use most of the time. Heck, I paid less for my pickup than the latest ML's cost. The vehicle gets a whole lot more use than most of my detectors.

As for the TDI, I use it for coin hunting in a park when not relic hunting or nugget hunting, so it does get more use. However, if it had cost even half as much as the newer ML's, I probably would have passed on it also. Not being rich, I have to decide the best place to spend what little money I do have.

I am sure there are people out there who have a whole lot more money or do get to nugget hunt sufficiently that they can justify spending a whole lot more than I do for a nugget machine. For them, it makes sense to try to buy the best, but for me or people like me on limited income or limited time to nugget hunt, it doesn't make as much sense at all, especially when one thinks that I managed to find a nice large nugget with a detector many think isn't what they would use because it is a VLF. Personally, I will use what I feel might work best from my selection for the area.

Reg

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Good points Reg,

Sounds like I need to take one out and put it through the paces as I mentioned earlier and there is indeed a need for an entry level PI and the TDI seems to be filling that niche nicely as well as having the ability to be used for coin/relic hunting.

Minelab has now made great strides in the ability of the GPX 4800 and 5000 to ignore EMI and combined with the new and improved timings we have depth and stability like we have never seen in our hobby before. The cost may seem high, but I think it is more the economy perhaps because when the SD 2000 came out it cost about 5 ounces of gold at spot and now still we are looking at about 5 ounces worth for the GPX 5000 :zapped: I think one needs to perhaps focus on the value of the detector and it's abilities as opposed to cash value and decide if it what will fit their hunting style and time allotted as you said. Sometimes cost can be a secondary issue to performance...

There is also a much better iron discrimination as well as a coin/relic and salt timing for coin and relic hunting on land or on the beach that work quite well under the right conditions.

Living in the AZ desert it is only logical for me dealer or not to have the best available as I am able to spend allot of time nugget shooting.

All good detectors deserve credit in my book and as long as they deliver what they claim they are a welcome addition to the hobby. I have always been more loyal to what fits my needs as opposed to the name on the box. Just as I will only sell what I use and am qualified to assist and train those new to the hobby or just wanting to upgrade to a different model.

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[

Right now, I know of a particular low powered PI that recently had some unique changes made that further enhanced the design. This new detector is now super quiet which effectively allows for deeper detection yet. I am hoping Whites elects to buy the design and bring out a PI aimed at finding the small gold. This, in my opinion would be a very smart move since they could capture a unique market that really should be targeted, in my opinion. So, we will see.

Reg

Hi Reg as usual good info for sure I would be most interested in trying the low powered PI that is as sensitive to small gold as a vlf but still immune to hot ground---heck most of the gold is in the gram and lower sizes-that would be a very good move for whites--Thanks Mike C...:ph34r2:

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Please excuse me for taking this subjext off track: George... Seeker.. have been missing you! Glad to see

your post...

Now back to replying to White's TDI... Mike C, I agree with you about Regs post... about a unique market that needs to be targeted...

I believe most of the eluvial gold is small bread and butter grains averaging about six inches below the surface down to bedrock.

It seems this "six-inch depth" (if it exists), is the boundary where the average mosture changes from surface wet to dry during a normal year weather cycle. The dryer ground can act as a temporary false bedrock...

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