Whites TDI Pro in Silver Country [including Infinium Comparison]

Jim Hemmingway

Hero Member
Jan 26, 2008
791
1,624
Canada
Detector(s) used
F-75, Infinium LS, MXT, GoldBug2, TDI Pro, 1280X Aquanaut, Garrett ProPointer
Primary Interest:
Prospecting
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Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Wow--what an incredibly technical post Jim--you really know your stuff. This post bears re-reading many times--lots and lots of information to digest. Well done, as usual. And, by the way, nice finds!

All the best,

Lanny
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Jim ! WoW ! I had to read it Twice . Great Report :icon_thumleft: :icon_thumleft:
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Extractor and Lanny...thanks fellas, yep this write-up was a real PITA. So much to mention to cover everything off properly. No worries, these posts will stay here for good. I'm mighty tempted to suggest that if anyone wants an original copy to stick in their files to PM their email addresses. Maybe we could try it and see how it goes...

Jim.
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Jim,
I've enjoyed reading some other posts you were involved in relating the use of the TDI machine to things other than gold and this is superb follow on post to the earlier ones. Your information truly indicates how versatile and useful the machine is with the understanding that no machine is perfect. Then throw in a few techniques to understand what is in the ground before one digs it and the machine really shines.

Thank you for your time and information...........63bkpkr

As a side not, I appreciate your inputs all the more as the old Whites 6000D coinmaster could be super tuned so that by the flipping of a few dials and switches one Knew what was in the ground (coin related not for mining) before digging and that is absolutely awesome information to have.
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Jim,

Since I have both a TDI and Infinium, your reports are invaluable. Thanks a TON !

I wish you continued success in your excursions out in gold and silver country.


JC
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

JC thanks for looking-in here. Iā€™m familiar with your posts and appreciate your comments a good deal. Thankyou.

ā€œYour information truly indicates how versatile and useful the machine is with the understanding that no machine is perfect. Then throw in a few techniques to understand what is in the ground before one digs it and the machine really shines.ā€

63bkpkrā€¦I am glad you made the above comment because that is exactly how this report should be interpreted at least for the application described. Iā€™ve yet to discover any detector that can handle all tasks perfectly. Certainly the TDI Pro is a capable, versatile unit suitable for many applications and served us well searching for natural silver.

It really shined in areas inundated with iron junk. In low conductive tone mode, GB adjusted to GB9 this unit was a real ā€˜scroungerā€™ at finding low conductive silver while eliminating most higher conductive iron signals either outright or by acquiring the lo-hi-lo iron tone. Using a 5ā€ round mono coil in such conditions is a real benefit.

We did our best to identify this unitā€™s capabilities for this application and we feel the unit does an admirable job. The search conditions encountered in our camps are as challenging as any electronic prospector is ever likely to encounter. In bygone times it was hard to imagine using a PI unit over iron-ridden tailings or mining camps. That is now entirely possible with either of these units as described in the report.

Jim.
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Jim, superb post, it's definitely detectorist's brain candy, many thanks amigo! I've kept this one for my records, great post!. :thumbsup:

HH

PennyFinder
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Thanks PennyFinder...hey if you want a good copy I am quite willing to send you an original copy.

Jim.
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Jim, That is an outstanding report! I know that it will take me many repeated readings to extract all the knowledge contained within. Owning both these machines this report will be an invaluable tool to help me better understand the capabilities of them. I will pm you my email address as I would like to have this for my permanent files.
Thank You,
Merton
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Thanks Merton, an email with both reports has just been sent to you.

You can figure I'm always interested in hearing anything you might have to say from your gold hunting experiences with either of these units. :)

Jim.
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Hello Jim Hemmingway... Jim Straight here.... I post as oldestjim on this forum and as i have one of the first Infiniums off the line (it has been modded for the monos) and an early White's TDI "hole" detector I'm most impresssed by this post!

While Googling I happened upon your AMDA posts regarding the electomagnetic properites of soils which is most intersting to me as I have both a Teknetics T2
and a Fisher Gold Bug Pro that has the abilty to measure the magnetic susceptibilty of the soil... to get to the point; the google post which referred me to your post on the AMDA was limited out (I'm not a forum member) and I found
what little I was able to access most valuable information I have ever read...

It would be great if you would post more information on undug soil magnetic proprties regarding a targert viz disturbed soil... The is a way could be another explaination regarding the halo effect..
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Howdy Jimā€¦thanks a million for those kindly comments. You can bet your bank balance I appreciate it. As I look back in time, it is hard to imagine that I very nearly did not post this article. I felt it was too technical and lengthyā€¦but it seems to have worked out OK.

The magnetics resulting from various iron minerals are interestingā€¦and seriously impact what can be achieved. A result is that over the years Iā€™ve paid particular attention to them. So, its gratifying to see that write-up attracted your interest as well. A few friends, Ty Brook and our good buddy DJ in El Paso have been quite helpful as mentors on this subject in recent years, and certainly deserve recognition here for their roles in helping me gain an understanding on the subject. These two fine individuals have given freely of their time and knowledge for which Iā€™m very grateful.

As to undisturbed vs disturbed ground magnetic measurements Jimā€¦ frankly I have not looked further into the matter. Iā€™ve been content to understand the differences between these soil conditions with respect to target depth and ID and apply the knowledge accordingly when in the field. I believe it has made the difference to digging good targets many times over.

Iā€™d rather not enter the long-standing debate about what exactly is responsible for the improved depth and target ID / discrimination experienced over ā€œundisturbedā€ natural ground. I donā€™t have a definitive answer and neither does anyone else, but Iā€™ll make a few commentsā€¦

Many hobbyists suggest a ā€œhaloā€ effect as the primary reason for improved performance in undisturbed ground. Other than iron oxidation, which is essentially maghemite, I donā€™t subscribe to the halo theory with conductive metals. Yes, other than perhaps very pure gold, precious metals and/or alloyed constituents may very well react with chemical substances in the soil resulting in molecular leaching / deposition into the soil. However, my view is that the amount involved cannot possibly sustain electromagnetic energy in the form of eddy currents sufficient to return a measurable signal. Its tough enough for a sensitive metal detector to give a useful response to disseminated precious metals in small rocks, and certainly detectors will not respond to non-ferrous chemical residues at a molecular level IMO. But heck, Iā€™m prepared to stand corrected by anyone at any time.

I am more inclined to a view that metal detector performance over disturbed ground struggles either from the loss of electrical alignment / continuity within the disturbed soil, perhaps further aggravated by the disruption of the magnetic fraction of a soilā€™s composition. Thatā€™s just guesswork. What does matter is that we can identify the effect of disturbed ground on metal detectors vs undisturbed natural ground and this phenomenon is readily acknowledged by the manufacturers as well.

Hope the weather down your way has allowed you to get out and about in the goldfields. All the very bestā€¦ :)

Jim.
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Excellent presentation, Jim. I experienced similar results on my TDI while hunting for sub gram gold nuggets 45 miles north of Imlay, NV around Placerites, Rabbit Hole, Rosebud, Scossa, etc. With the ground mineralization at 83, according to my MXT, I was unable to move the GB down enough to acceptable levels to find any sub gram nuggets but was able to disciminate out most nails and bits of iron. I did find some bullet fragments and even a 3 ring bullet with this high mineralization at Placerites, where the iron mineralization seemed to be very high.
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

A truly GREAT post, Jim! Not only did it cover the machines well, but it also clearly shows you KNOW the machines. That is the base concept others should learn from this and other fine posts.... Know your machine! Tnx. TTC
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Thanks Jim for adding your comments. Feedback from gold prospectors like yourself who use this unit are exactly what I want. Your comment highlighted below...

"With the ground mineralization at 83, according to my MXT, I was unable to move the GB down enough to acceptable levels to find any sub gram nuggets but was able to disciminate out most nails and bits of iron."

If you happen to look back in here Jim, do you mind my asking where the TDI ground balanced in that area? If I'm interpreting your remarks correctly, it sounds as if you set the GB fairly high to eliminate nails and so forth...while searching for higher conductive gold in the high conductive tone mode...

Jim.
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Well howdy TC, geez your post caught me by surprise. :wink: I haven't been following most of the posts too much now that summer is in full swing here in the Great Lakes area, but I seem to recall a short while back you had left for the outback in your RV.

So, let me ask you how you have been progressing with either your Goldbug2 or the GMT....

I felt you did a great job of presentation in your video. You kept it straightforward, took your time to make sure viewers could understand what was happening. Please don't be hesitant to add a few comments here about your further experiences. Anything you might say will definitely help me Terry as I've got a goldhunting trip planned for the end of the summer over to the Quebec / Maine border country...and yep...I'm taking my Goldbug2 along with a few other units that should do OK.

Jim.
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Hi Everyone,

On a different forum Iā€™ve encountered two separate comments that Iā€™d also like to address here. The first comment as I understand it, was about an interpretation on the part of a reader whereby the third chart in the article was interpreted as to somehow imply a direct relationship between VLF target ID VDI readouts and GB placements on the TDI Pro ground balance scale. The second comment was about the utility of evaluating target signals when targets could be just as quickly dug up. I think we all realize that is not necessarily the case in many instances.

It is not possible to draw direct correlation between VLF target ID readouts on high conductive silver ores to their GB point on the TDIā€™s GB scale. Sure, we can identify trends whereby high conductive ores will tend to locate in the left area / lower #ā€™s of the GB scaleā€¦ silver coins are another good example. Lower conductive ores generally locate in the right area / higher #ā€™s of the scaleā€¦ nickels are a good example. And the remainder of target conductivities generally fall somewhere in-between.

Unfortunately, some of our silver ores, despite having similar VLF target ID readings, have quite variable GB placements on the TDI ground balance scale. The TDI does not establish GB points based on a phase shift relationship. Moreover, other factors pertaining to the structure / character, purity and type of inclusions, size, shape, and perhaps even the profile presented to the coil very likely contribute to a silver oreā€™s GB placement on the scale. Possibly other factors enter into the equation as well.

Look at the chart referred to above when you have a momentā€¦itā€™s the third chart down. This chart is only intended to draw the readerā€™s attention to an observation that target depth on high conductive silver decreases as the target GB point approaches the TDI Proā€™s operating GB setting. The closer the target GB point is to the operating GB, the more significant is the depth loss.

The MXT target ID numbers assigned to the ore samples are not intended to attempt to establish a fixed relationship with GB placements. The target ID numbers were simply used to further identify the individual samples, and to illustrate that the entire high conductive range for silver ores is represented in the chart. The MXT itself was selected only because many hobbyists are familiar with the unit.

Look at the corresponding GB numbers in the chart. There is no identifiable direct relationshipā€¦ linear, logarithmic, exponential or otherwise. In fact you will see that there are a number of ores at widely scattered VLF target IDs that have similar TDI GB points. Conversely, you can readily see a number of silver ores very close in VLF target ID but with quite variable GB points on the TDI.

Note for example, that the four penny / dime silver ores have a GB span between GB3.5 and GB6. More, there are silver samples with VLF target ID in the upper pulltab range with TDI GB points of GB6.5. ..very close indeed.

Perhaps this subject should have been explained within the text, but we simply overlooked doing so in the much-reduced version that was posted. There are other interesting nuances associated with the unit that were also excluded from mention in the posted version. I anticipated that if readers noticed or commentedā€¦that would be a suitable time to address them.

Now as to the second comment about target retrieval, if an operator can dig a target in the moment it would take to evaluate a target signalā€¦then by all means do so. But that is not the case over much of our area. By and large, our ā€˜groundā€™ is a rocky substrate cemented together from the effects of pressure and weather over as much as a century. A target buried at 18 inches may well require 10 to 20 minutes of hard work to expose. If one can acquire a lo-hi-lo iron tone (as is also briefly referred to on page 28 of the Proā€™s manual) and avoid expending time and effort to dig an iron drill rod, then that too is time well spent. Digging deep holes in our concrete-like rock substrate is not a chore to undertake lightlyā€¦we understandably check the target for the iron tone prior to digging when searching for high conductive silver.

To summarize generally, the report touched on many features and nuances associated with the full potential of operating this unitā€¦ for the sake of completeness only. In a prospecting context the settings could be as simple as delay at 10-usec, tone control set to ALL, GB ON and balanced to the soil, barely audible threshold, gain set as high as possible with reasonably stable performance such that you can hear faint signalsā€¦and hunt away. Dig all signals if that is your preference. Or try to acquire the lo-hi-lo iron tone first to save yourself some digging. Or search low conductives only in high iron junk areas by either ignoring high conductive signals in the ALL position or flip the tone control over to LOW conductivesā€¦and simply not hear high conductive signals. But you can choose your preferences based on complete information presented in the report about how this unit can be operated. There is no law saying you canā€™t select how you want to run the machine. Keep it as simple as possible to get the job done in the field.

Jim.
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Just the opposite, Jim. Reading back on my notes and posts it seems that I recently (now that I am not using the TDI) confused high tone with having the switch in high conductor mode. I was in Low conductor mode with the GB on 8 1/2 to 9 1/2. It seems that the sub gram nuggets above .3 gram can be picked up by the TDI but only 1 to 3 inches from the coil if one moves the coil at a slow pace over the ground. Less than .3 grams ........ good luck.

One loses depth incrementally by increasing the GB. Thus, a higher mineralization will cause one to increase GB and one will lose some depth. However, lacking the power of the ML4000s for sensitivity and depth, the TDI does have some compensation. It is light weight because one can hip or chest mount the unit and only have to swing the shaft and the coil. Also, once the GB is set for the conditions, it is a very smooth running detector in gold country with high mineralization. My only wish was that it had more power for greater depth and for increased sensitivity. I walked and worked next to 2 ML4000s for 4 to 5 days and each of them found about 15 sub gram nuggets apiece to my zip. I was, to say the least, dissapointed. They were able to detect sub gram nuggets a lot deeper than I was able to with the TDI.

I would say that Whites would have a winner if they were to increase depth and sensitivity with increased power. However, currently, to compare a ML4000 or 4500 to a TDI, at present, is no comparison and to say that the cost is much less at 1/2 the price is not a good trade off if one spends 2 or 3 times that amount on a trip to get to gold country to do any detecting. One wants a detector that is going to produce after one spends the money to get to a detectable area of the country or on a long trip to Austalia. $1,500 to $1,700 is not chicken feed and neither is a few thousand dollars in travel costs to get to an area to detect gold nuggets. Again,with increased power for greater depth and sensitivity, the TDI will come out on tops eventually.















Jim Hemmingway said:
Thanks Jim for adding your comments. Feedback from gold prospectors like yourself who use this unit are exactly what I want. Your comment highlighted below...

"With the ground mineralization at 83, according to my MXT, I was unable to move the GB down enough to acceptable levels to find any sub gram nuggets but was able to disciminate out most nails and bits of iron."

If you happen to look back in here Jim, do you mind my asking where the TDI ground balanced in that area? If I'm interpreting your remarks correctly, it sounds as if you set the GB fairly high to eliminate nails and so forth...while searching for higher conductive gold in the high conductive tone mode...

Jim.


Just the opposite, Jim. Reading back on my notes and posts it seems that I confused high tone with having the switch in high conductor mode. I was in Low conductor mode with the GB on 8 1/2 to 9.
 

Re: White's TDI Pro in Silver Country [including Infinium Comparison]

Thanks Jim, your post certainly clarifies your recent experience. Yes, it is easy to inadvertently describe your tone set-up as ā€œhigh conductiveā€ when one really intended to say ā€œhigh tonesā€ā€¦Iā€™ve done it lots. There is no doubt you were operating your TDI correctly in pursuit of low conductive goldā€¦and those settings would eliminate most nails and other high conductive iron in the low conductive tone mode. It makes perfect sense now.

Your remarks about nugget size detectable by the TDI in a ground-balanced condition seem about right too. The fact is Jim, when testing fairly compact, fairly smooth solid little nuggets, I have observed that about half-a-gram to one-gram seems to be the size where either of my PI units start to click in with improved depths. I say ā€œsmooth solid little nuggetsā€ because I have plenty of nuggets at the one-gram size range but with lots of ā€œcharacterā€ that will barely respond even when tested practically on the coil. For this reason I believe that PI units do overlook nuggets in this size range at least.

There seems to be an endless controversy surrounding how deep small pieces can be found by various PI brands. On the one hand, I can see how a small nugget might only be detected on the outside rim of the coilā€¦but yet the operator may mistakenly think its in the center of the coil and start digging a hole. Its easy to see how that nugget might fall into the holeā€¦eventually be scooped outā€¦.resulting in a report of such and such depth for that size piece.

On the other hand, regardless of how nuggets may or may not have been detected by the ML units, obviously your unit did not detect similar size nuggets. You make a valid point in my view. All that occurs to me is that given your side-by-side experience, and the fact that you are a dedicated gold prospector, a ML unit would be a better choice if you can swing the cost.

Iā€™ll be heading out to the border country of Maine / Quebec to do some nugget hunting later in the summer. Your experience has made me think more about how Iā€™m going to pinpoint a small target signal to be sure about where exactly that target is located if it is shallow. Been thinking that Iā€™ll tilt the coil perpendicular to the ground to see if there is signal off the tip of the coil. If so, then Iā€™ll know for sure where the target is located and avoid possibly digging a hole off to the side.

Thanks Jim for getting back to me. Forums are for exchanging information and expressing oneā€™s views, and frankly I appreciate hearing from a seasoned pro such as you. There have been a few hints from a few sources that Whiteā€™s may be working on improving the TDIā€™s sensitivity, weā€™ll just have to wait and seeā€¦

Jim.
 

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