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Having bought both The TDI SL and then the TDI Pro it was only matter of time before I started comparing one against the other and what I found was quite disturbing, With the SL you get a nice light weight package and on the surface it's only down fall appears to the limited power supply and after a short time I managed to increase the burn time by just over an extra 50%, With the TDI Pro word soon got around that if a person was to turn the Ground Balance off then the depth would be greatly improved IE with the GB ON testing it using a US Quarter the TDI Pro would see the coin at a distance of 12 to 14 inches, But by turning the GB off the Pro can see the Quarter at about 18 to 20 inches +/-, But with turning the GB off the TDI then goes in to what I call a Smoothing mode where it adjust the GB slightly and as long as a person maintains a level sweep height the TDI will remain quiet as long as there are no sudden movements up or down in height, So all that was said about the TDI Pro stands True, SEE the video below, So Armed with what most folks knew about the TDI / TDI Pro's, It would be very easy to assume the same could be said for the TDI SL, Sadly this is not True and the results could not be worse, With the Ground balance on Both machines are equal on small targets with the Ground Balance ON ?, but once the targets start to get bigger than a large coin then the Pro starts to get ahead and with the GB off on a target that is 6" Across/round then the Pro will see it at distances that can be measured in FEET further than it does with the GB ON. Knowing this and doing the same tests with the SL with the GB ON all is equal to the Pro on targets about the size of a Quarter or less, But REMEMBER that smoothing effect that the Pro does with the GB OFF, well the SL does it when the GB is ON now this has a serious effect on the SL because once the Item goes in front of the Coil it gives a faint woo sound at 15" to 16" then after about 2 maybe 3 passes in front of the coil the distance then drops to about 12 and a half inches, Now remember that smoothing effect again, Well what is going on here is that the machine is actually tracking out the Item to a degree and I am sure that many would agree that that is a bad thing, and the only way to make the machine see the Quarter again at 15 to 16 inches is to bring the coin up to the coil and almost overload the signal which resets the smoothing effect and then it will see the coin at full depth again, but in the real world you cant do that so if you do here a faint target Do Not keep sweeping the coil over it or it will be Smoothed or GB'd out and if that happens then you need to sweep the coil over another patch of ground and then sweep the target area again, Once you get within the normal detection range you can proceed as normal. Now once you turn the GB OFF this is where it all goes wrong again Because for One you loose that smoothing effect because it no longer does it PERIOD, And Two the distance that it can see the Quarter very faintly is now 11 and a half inches using the same 12" DF Mono and for some reason that overloading trick now has NO effect so that 11 and a half inches is all you will ever get, Steve once posted that the TDI SL felt like it lacked the Horse power of the TDI Pro and in a way that is true ?? AND if this is the case when you consider that in the GB off position it should be running at Full power and that it is running like the GB is ON and with the GB ON it is Smoothing out everything which should only happen in the GB off Position is causing a depth loss which is already running in a mode that is limited It appears that it has the same features as the Pro but it is wired back to front. If you get my meaning. And I am sure that this is why the MXT with the factory 12" can out run the TDI SL. This now brings us to the Coils, we all know that a small coils can see those tiny bits, But the 12 DF is One 12" coil and One 6" coil, yeah ? And that the 7.5" DF is One 7 and a half inch coil and One 3" coil ,Well this is where All Coils are Equal because the 7.5 has the same depth as the 12" DF on small Items and both of them Struggle to see Items smaller than 0.17 grams which is quite small really where as the Average normal VLF will see bits down to 0.02 to 0.03 grams even my 15" MXT Max coil can see them, Where the DF Coils excel is on things about half the size of an Airgun Pellet and bigger, On coins like Tiny Roman Minims these coils are Awesome but just don't expect too much from them in prospecting venues, Please watch this Video to see the Smoothing effect in action, And Note the depth he gets on that Nickel with the GB turned Off. Thank you,,, John

After all the excitement and comments about air test I decided to do several test using my TDI SL with stock 12” coil. First off I charged the battery pack (11.35v). Set the machine in a very good area with the coil elevated with the following settings: Gain max Ground balance off Pulse 10 Conductivity switch, all At these settings, using a US nickel I got a solid 12 to 12 1/4” air test, light, but repeatable audio. I checked the machine every half hour and there was no change in air test distances. After four hours still no difference. I turned machine off and checked the battery pack voltage (9.63). Amazing discovery, the machine must have a very good voltage regulator, for the machine to perform the same as with a full charge pack. One notable observation: Gain of 7 to max gave the same results in air test, no difference, even after 4 hours of continues running. Drop the gain to 6 and the nickel could not be heard at 12”, but around 11 ¼”. Fast forward: Installed a fresh set of Rayovac batteries in my battery pack These measured a total of 12.8 volts. Did the same set of air test and the results are as follows: Air tested a nickel at 13 1/4”, faint but repeatable audio. This distance was continues for around an hour, then dropped to 12 ½”. After 2 hours the air test was the same as the stock rechargeable battery pack. Shutting down the machine and checking the voltage indicated 11.35 volts. I know you can buy a battery pack with 14.8 volts which will obviously increase the depth performance, but I wonder what the maximum voltage that could safely be used in my unit!

I recently bought (from Steve) a White's Sierra Pulse Pro (SPP) PI detector which is effectively a TDI/SL without a delay adjust (locked at 10 microseconds) and without a conductivity switch (locked in the 'All' position). When I took it down to the creek with the Minor John 5in X 9 in folded mono coil I was disappointed when it floated. Apparently most coils are either for dry land use (thus lightweight) or for underwater use (heavy). I've been spoiled by my Fisher Gold Bug Pro 5 inch round DD which exhibits (by design, I'm confident) neutral buoyancy, meaning it neither sinks nor floats when placed under water. Besides the three coils that Steve included in the sale I now have a fourth -- a 3.5 in X 7 in White's coil, which I understand was an early (prototype?) version no longer available. Unfortunately it joins the 5x9 Miner John, the White's 12 inch "Mono Aussie", and White's Super Pulse 150 (mm diameter mono) as floating searchcoils. Of these four only the 12 inch Mono has an open structure. There are other coils available from White's and from Razorback (Miner John) but they don't seem to advertise whether or not they float, sink, or are neutral buoyant. Furthermore, as those of you who own PI detectors know, they aren't cheap, so buying with the hope that they will work well in water seems like a costly hypothesis. I had an idea, which seems crazy, but then occasionally crazy ideas work out. I have a Garrett BFO Master Hunter detector I bought as a backup (for a Garrett's Groundhog 15 kHz VLF/TR) back in 1979. BTW, it still works. I also read in Charles Garrett's 1985 "The Advanced Handbook on MODERN METAL DETECTORS"

Can someone tell me who makes the Jimmy coils for JS? Thanx

I'm new to the forum which is excellent, I'm thinking of upgrading to either the ATX or the TDI pro, the machine will be used mostly on the beach, but an ability to coin shoot would be excellent. Any feedback would be appreciated.

The wait is over my new TDI pro has arrived and I am impressed, The Build quality is about the best I have ever seen on any Detector, I knew it would be good but I did not expect This and the attention to detail is incredible, All of the Controls are firm yet smooth, it is about as perfect as anything could be, I cant wait to get out there and get in to it, John

Hi everyone I am stuck with a choice to make, The problem is I have a TDI SL and I been wanting the TDI Pro for about 5 years but they do not import it over here but now Whites have agreed that I can have one due to some leeway in transporting the batteries, I have always wanted the pro and in the end I bought the SL Only because they did not import the Pro and now I can have one Is it worth my while to buy it, Being so close to getting it is now having a knock on effect of am I doing the right thing, There is less than an Inch when it comes to depth between the 2 machines, But the real Bug Bare for me is am I ever going to be able to turn the gain above 5 or 6,, I have seen a guy doing those tests comparing all the PI's and he has the Gain running flat out, and it seems to be running very well, I would go as far to say Smoother than my GP 3500 use to run, If anyone has any info of factual use that would be great to here your views, along with how high you can run them etc because if it cant go above 5 or 6 then my SL is going to be deeper maxing out at 10, There seems to be many folks talking about how the Pro warbles is it really that bad, baring in mind I run my MXT and the GMT just where it starts to warble depending on my mood and patients, I am not bothered about chest mounting the machine because I like to get away from the machine when I am digging So am I making the right choice, ?? Note I was going to buy one of the 4500s but because of the junk over here it is impossible to work a PI without some form of Disc system, Yes I do want the Pro,, Is it a wise choice ?? Is it any better ? can I run it up around the 8+ mark without losing targets due to the warble?. the SL is a great machine and I have some new battery tests coming up which I will add to the Battery Thread, Thanks Guys,,, john

Posted the following on a particular site and almost immediately picked up ridicule for adjusting the TDI in the manner stated. I'm a very open person and can take constructive criticism if need be. After several hours hunting with the TDI SL I finally found the perfect settings for this particular site. This place is littered with the waste bi-product of burnt coal over many years. Much of the waste is small in size, ranging from BB to marble size and the smaller pieces easily attract to a magnet. In addition to that, the area is littered with nails ranging from 1 to 4" in length and some up to 4" deep. These nails, especially the larger ones give a good audio, especially with a ground balance of 8-9. After a suggestion from Reg, I began adjusting the GB to 4-5 and if the signal became inconsistent then the target was most like a nail. After a lengthy amount of hunting I decided to run the machine at gain max, pulse 10 and GB of exactly 5. Surprisingly the false signals all but stopped and I started finding old copper pennies some being wheat pennies in an area where I had gridded off and cleaned out of all good targets. Amazingly, I still can't believe I had missed that many targets with my other machines. Now my next plan is to locate, what I believe to be good non-ferrous targets with the SL and mark each location. Then use my regular VLF machine and see if I can detect each target and note the audio responses given. Many things to consider in this journey, very excited to say the least. Well it seems some people on other sites think it is a sin to adjust the TDI the way I did in the following statement. I want to add one thing; the ground I hunt is very unique. All I'm stating below is what I observed and found to be true at this site on this day. I'm very well aware the best settings would be GB 8 and pulse 10, but the ground does not allow the best settings to be used to produce what I'm looking for. Coins mixed in with heavy coal waste made of iron, BB size to marble size to be exact. Well, went back to the same site where I posted, "perfect settings for this site" and hunted a small area not more that 60' from the prior hunt. Used the same settings "GB 5, pulse 10 and gain max" and off I went. After a short while I noticed a lot of clipped or inconsistent audio reports. Decided at that point to reduce gain to 7 and continued. Hunted a few more feet, still clipped audio, strange, so I stopped to analyze the area a little more closely, sweep in one direction and get a some what good audio, but the return sweep was either silent or chatter. Suspecting something was the cause I stopped and increased the pulse delay up a tad, nothing changed. Continued to increase the pulse until I reached 17 and suddenly the audio came through as a loud, almost overload low tone. Thinking it might be a nail; I dug and out came a copper penny at less than 4" deep. Now to say the least, I was excited and puzzled. Decided to start over where I started hunting and experiment using a pulse rate of 17. A few moments later came the same type of loud low tone. Thinking there is no way I missed that one my first pass I changed the pulse to 10 and the signal all but disappeared. Increased the pulse to 20 this time and spent over 5 minutes rotating around this target checking from every possible angle to see what might be causing the anomaly, switched the conductivity switch to all and still a consistent low tone with nothing else mixed in. Now one must keep in mind I'm using the stock 12" and at times it is very difficult to exactly pinpoint where the target actually is. Changed the pulse to 10 and the low tone practically disappeared. Now I was wishing I had brought my Deus to recheck some of these inconsistent signals, maybe next time. Well anyway I dug a nice plug and out came a wheat penny at less than 5" deep. I was very excited to recover something from an area that quit producing years ago. Continued hunting with settings of pulse 20, GB 5 and gain at 7, and found many more coins dated in the early 60's all within a 3' path some 60' long. Already planning what I'll do my next hunt. What I learned from this hunt: Regardless of what some may say, don't assume you have the best settings for any site especially the sites where coal waste has been discarded for many years. I'm suspecting the partial or complete cause of the anomalies is the small BB size waste particles from the coal fired furnaces that will easily attract to a magnet. In fact dropping a strong magnet into the same hole where a coin was revealed exactly that. I'm relativity sure I need a mono coil, but undecided as to what I'll get. More reports to come.

Steve has this article been removed because I have tried to read it a few times and I keep getting the Error 404 page?? Thanks, john

Steve, I just read your TDI Moore Creek Review and In it you said the you managed to run the TDI At Full Gain, Yet I have heard tales stating that the TDI is Noisy, So what I am asking is it the Location that made the TDI Quiet so you could run it that Hi or Is The TDI pro more Noisy than the TDI you Have/Had, Because I have read many times that most people can not run them about 6 on the Gain,?? Thanks Steve. John

I recently acquired a through hole version of the TDI with the sole intent of modifying it to run the 8 uS pulse delay. Does anybody know the procedure for this? I will also need help in getting a coil to run properly with it as well. Any assistance would be greatly appreciated. Thank you.

Well a good while back I finally decided and purchased a Whites TDI SL. As always, each new machine has to pass through my test garden. Did some detailed work in my test garden yesterday using the TDI Sl. First results are very promising. Settings were, pulse delay 10, ground balance 7 ½, gain max threshold just audible. I have a copper rivet buried at 7” about the size of the end of a pencil eraser a 6 ½” quarter, dime, nickel and penny along with each at 4 ½” deep in a different part of the test bed. In addition to these I purposely left nails where they were when I planted the garden over 7 years ago. Please keep in mind these were the depths when I put them in the ground, so the exact depth is not known after 7 years. Starting off in high conductor mode each (except the nickels) gave a very good, smooth audio in every direction except the nails which gave a completely different sound, very much different. Keep in mind I’m still in a steep learning curve, by no means close to experienced but having a fantastic time on my journey. After listening to the differences between the coins and nails I reduced the gain to about half and listen to each target again. I continued reducing the gain little by little until the deep coins and rivet ceased giving a audio response and that was about gain 3 ½. Raising the gain back to 4 and the coins gave a very faint, low volume tone. Wanting to play a little I raised the pulse rate, re-ground balanced and checked each target with a gain setting of 6. The biggest difference came when the pulse rate was set above 20. The coins still gave a good audio, but the rivet, which is very small compared to the coins, became difficult to hear, very statically, extremely low in volume. All in all I had a very enjoyable evening, very educational. Mark Gillespie

Whites TDI SL Went to an old school where the coal cinder waste has been dumped for years and hunted for 1 ½ hours. This area has been grid hunted for years and I was sure there were no goodies left to be found. Well wrong again. GB to a little over 8, pulse 10, gain 10 and off I went; very first signal was a wheat penny at 4-5 inches and perfectly vertical. You can see the scratch I made with my shovel. Wow, was I off on my pin pointing skills. Couldn’t believe how I could have missed that one because it gave a very good, consistent audio response from every direction. One thing I noticed, it didn’t give a double beep like a VLF machine would on a vertical coin. Thought I had the sound nailed down, but was I wrong. Started digging nails, three to be exact, all sounded fairly good but I could tell there was something wrong, but I’m learning, so I dug anything that sounded remotely good. A few minutes later, not more than 10’ from the penny, another signal that sounded different, not sure what sounded different, still learning. Wow, a silver dime and not quite 5” deep. Now I am wondering how I could have missed that one, not a clue yet. Well anyway, the next two targets were nails, then another perfectly vertical copper penny. Had a very good hunt, for an area that basically dried up over a year ago. Wonder what I'll find once I have a little time on this machine?

Comparing the TDI SL and The MXT Pro (12") I was wondering if anyone as Compared these Two Machines, Because the SL is an in between machine, Between it and the ML 5K, I have been wondering about these two machine Because I have Read Stories about people Pulling One Ounce Nuggets at 18" At Gains Creek with the MXT fitted with the 12 inch Coil, And I have seen Coins come up at over 13" with the same setup with the Gain set between 6.5 to 7, Yet I have never heard about Deep Nuggets found with the TDI SL, and I have heard about people digging Bobby Pins on the beach with the TDI's at 16" to 18", In Air Tests My GMT with the standard 5X9 coil versus the TDI SL, On a Round Flat 1 1/4ozt Lead Nugget TDI SL = 18" and the GMT = 21" set at 7'5 (pre set mark) So I could do up to 10 if conditions Allow, But considering the SL has a 12 DF mono I would never of expected that to happen, Like The MXT when you Turn The GMT up you Can hear it Changing Gears so to Speak as it Multiplies the Gain, Has anyone here found any Deep Nuggets with the SL, I know that someone in OZ found a 5.6ozt nugget AT 32" using a 20 NF Coil, I have picked up Large Iron at have 4 foot deep and the subway Tunnel at over 6 feet deep, But as winter is all but over I am hoping to get out and do some testing ect, Thanks Guys,, John

Great updated thread with photos by Jim Hemmingway at http://www.treasurenet.com/forums/metal-detecting-gold/461891-white-s-tdi-pro-northeastern-ontario-silver-country-revised-edition.html

I was curious just how a dual D coil would work on a TDI and this is what I found but first, I need to say my Dual D differs a little from ML's or Minelab's design a little. The reason is simple, I wanted to use what I already had made and just modify the mounting. My main TX coil looks basically the same is those in the posts of the dual D coil, but my RX coil is a little different. Instead, my two D coils are part of one large winding shaped into two D's, with a half twist in the leads passing through the center of the TX winding A simple half twist puts one winding out of phase with the other RX winding, so cancellation is the same. Ok, here are the results. First, the coil is quite sensitive, very quiet, and requires no ground balance signal at all. At least, it doesn't at my house. The detector is so quiet with or without the GB on, it is clear that I could increase the gain and, thus, the depth when using this coil. The coil housing I used is a 12" by 9" so it is smaller than the factory 12". However, the sensitivity is close to the same I am also betting I can increase the windings in the receive with little to no major noise effect,and possibly a little gain. I also have an idea to increase the gain another way. Right now, I see a depth increase on the TDI since I can run with the GB off just fine even over really bad ground, but I feel I can do much better with a few other tricks. So, it is possible even the old detectors have life left. Reg

I am in the market for a pi detector for beach hunting. I cant afford new so used will have to do me. The TDI Pro is at the top of my list but I do have a chance of picking up a good GP3000 with DD coil at the right price. I know that the Minelabs are not to fond of salts so I am wondering would the GP compare in performance, depth wise to a TDI?

Hello Steve, I was going to wait until March 1 to see if Whites was going to come out with a water proof TDI or TDI SL. Not Going to Happen !!!! So....I purchased a new TDI SL and made a few modifications to make it at least "splash proof". Is it water proof....no. Will it protect against an errant sand grain or two, sea spray and an occasional splash....I hope so. I know it is not pretty, but you do what you need to do. Take Care....Jeff

Back around 2008 I was involved with the use of the White's TDI in a very big way at my mine at Moore Creek, Alaska. I made various posts at locations around the internet on our success with the TDI but never did get around to collecting it all together in one place. Until now. I just made a belated entry on Steve Mining Journal titled White's TDI at Moore Creek, Alaska - Summer 2008. Lots of gold nugget stories and photos there - check it out. Also added a page about the TDI itself I am still working on but a ton of information there at White's PulseScan TDI Metal Detector already so went ahead and posted it. 0.31 ounce Gold Specimen found with White's TDI

Hi steve, just thought I would drop a line on testing tdi at winnemucca 3 days. Ended up pretty good. walked a lot of the desert, found a lot of lead. Then I found a nice little area that has been over by numerous detectors before. The ground was to hot down there to run with geb off, so ran with it on Gain around 9 ground balance 9 to9.5 pulse 10 most of the time, low conductivity a little noisy but I could work with it fine.i havent weighed any thing yet nice heavy pieces though. Area I found I would test tdi against gb and there was two pieces tdi could not see at all. These were all flat pieces of vein very thin. Anyway was great weather after snow first morning, overall pretty pleased with first pi machine, especially knowing mineabs and everything else has electrified the ground here before me.

Recently got this tdi, have studied over and over everything I could get my hands on to gain a little knowlege of this PI. I have only hunted 3 times so far(6hrs.maybe) what a cool, machine never been around them but wanted to try one. First time out was overwelming, almost, wrote everythig down I did. 2nd. Time out was getting to understand it now, alot of experimenting found 8 coins and a lot of you name it.running in all full gain pulse 10 in this ground gb about 8. Wasnt sure if I had brought a long enough shovel for it's capability, wished I had a tape I dug 2 beer cans burried easily24 inches first 6 or 8 inches was dirt and rock then pure wet sand.It would have hit these even deeper, you guys that run these already now that. Trying to teach myself the different variations of targets, gonna take time for sure. Have a few questions I hope to get some answers to. By the way I ran 2 coils experimenting.(7.5-12") I did some air tests with some nuggets I have found with gb2, apparently the current doesnt hold well on porres nuggets under 6 grams, maybe my settings, but I tried with it set full power and didnt get much response on the porres, I think I read it cant hold current very well on targets like these, is that true and to what extent? Havent got to do any under ground testing yet ground still muddy and frozen. Thanks for any input here rick I want to take this to the desert shortly, now wondering if it will still go very deep on these big nuggets that could be over half ounce we now there are more here, just want some input on this dellima. just hoped it would go deeper than gb2 that have found several BIGnuggets here.

Last Saturday I decided to get out and enjoy the unusual, for January, weather here in N. Calif. I met my partner Reno Jim and headed for a spot we've hunted for years. We didn't expect to find anything, maybe a crumb that had been overlooked in all the trash. It was just a good day to get some exersize after the holidays. While Jim worked the banks digging trash, I started up a dry creek bed rechecking exposed bedrock I'd already hunted before. I came to a spot where a 10 ft section of new bedrock has been exposed. It looked like a gully washer had come through and blown off the overburden. It was just above a spot I had done well at in years past. I wasn't expecting anything as I had seen fresh dig holes further down stream. Within a foot of hitting the new bedrock I got a good signal which I knew for sure was a bullet. I scraped a bit of dirt off and the signal was gone. Checking the dirt, there it was, right on top, a nice little 1.5 dwter. Wow, that was easy. I wonder how that got missed. I moved another foot up stream, and bang, another signal. Again, I was sure it was trash, it was so big and loud. This one I checked with the pulse delay to see if it went away like a nail, but it was still there, so again, thinking it's a bullet, I scraped off the dirt and got the signal in the cup. It couldn't be a nugget, that first one was a fluke, the only one in all that bedrock. But, sure enough, out rolled an ugly 3 dwter encased in red quartz! At this point I thought I'd better call Jim over to hunt the rest of the spot. He'd been on a long dry spell. He hunted that spot the rest of the day but could only come up with one tiny little .1 dwt grain. I left him to clean it out and moved further upstream. Around the corner was more bedrock that I had hunted at least a dozen times over the years. A couple of nails later came a loud booming nail signal right in a little pocket of rock. And again, scraping the dirt out with the pick, again, I look down and see a huge flat nugget just laying there. I couldn't believe it! How could I have missed it before? Because it was SO big and loud, I just passed it up KNOWING it was trash. Geezz, you think I would know better by now. Glad I wasn't hearing nearly the iron trash of years past because I was using my TDI in low conductivity which knocks out the larger iron. We were both using the TDI SL with the 9x5 Jimmy loop. So, by the end of the day, we each had found one more small piece for a total of just over 1/2 oz. The big ugly slug weighs 5.7 dwt. Good start to the new year! Digger Bob

Editors note: Mark contacted me regarding the use of a PI, specifically the White's TDI, to try and get better performance on coins at a difficult location. I asked him to post here to get the ball rolling on the subject - Steve H The reason I'm asking these questions is because where I live all the old schools used coal for their heat source. After burning the coal the waste was spread out over acres of land to get rid of it. Most is the size of a bb up to maybe a small marble. It is some sort of iron makeup because it attracts to a magnet fairly easily. And as you well know a regular VLF machine is rendered about useless with the exception of very shallow targets. Over the past 7 years I have owned or borrowed each of the following machines and none can get any depth over 4" in these areas. The following is a list of the machines. Tesoro Vaquero, Tejon, Lobo Supertrac, Garrett A250, Teknetics Eurotek Pro, Fisher Gold Bug Pro, F75 and the LTD version, Whites XLT, DFX, V3i, Minelab Explorer SE, Etrac and CTX 3030. Please keep in mind, not all the machines were mine. Some were loaned to me just to try in this bad coal cinder ground. One interesting note about the Minelabs, when auto sensitivity is used the machine will throttle down to 8 or lower in these areas. Now you might be wondering why I'm so interested in this one particular area well it is because it was one a huge group of ball fields used back in the 40's right on up to the 70's. I have pictures of actual ball players and at times there were hundreds of people watching games. Now that said, there should be many silver coins at this location, but none have been found and I can only guess it is the ground. Because over the years we have buried coins at 4" deep that none of the machines mentioned earlier can detect and 4" is not deep for any of these machine. So my assumption is that the material robs the transmit signals from the machines to the point depth can not be achieved. I have talked to Carl at Whites and Dave at 1st Texas about these extreme harsh locations and actually sent them each a 4 pound box of this material to test. Dave suggested ground balancing to the material and using the motion all metal mode to hunt. This provided some positive results, but only to about 5" in depth. On the other hand Carl was working on a PI prototype at the time and could only provide his comment, which was, no VLF would be able to perform at these locations. After reading many of your post and watching your videos I decided to contact you for additional information. I sent Carl another message after reading about your postings on the Whites TDI and here is his reply. Re: dirt Quote Originally Posted by markg Carl, a guy that hunted the digging in Virginia swears that the Whites TDI will punch through this kind of dirt. I know you can agree or not on this subject. But the cost of buying one to try would be a gamble. What do you think? Quote Originally Posted by Carl-NC just tested your cinder soil with a TDI... it's actually pretty mild compared to my Australian soil. The Oz soil is strong and has a very tight ground balance setting, whereas the cinder soil is weaker and has a broader GB range. So I think the TDI would handle this stuff easily. Regards, Carl I guess I really would like someone close to where I live visit and try a pulse machine. That way I would know. I can provide an open invitation to hunt about any evening.

ATX, TDI, GPX. What is it with detector companies and three letter acronyms? I liked it more when they were called Coinmaster or Goldmaster. At least that gave you a clue about what the detector was supposed to do. The three detectors representing the state of the art in ground balancing pulse induction (GBPI) metal detectors. The Garrett ATX, White's TDI, and Minelab GPX 5000. You rarely see them all pictured together so I thought I would post one. Garrett ATX, White's TDI, Minelab GPX 5000 These three detectors are all very good at what they are basically made for, which is dealing with ground mineralization and hot rocks that make using VLF detectors very difficult. In particular VLF performance is severely impeded in extremely mineralized ground. In low mineral ground a good VLF prospecting detector running in all metal mode can deliver results rivaling PI detectors with the added benefit of having good discrimination options. Anybody doing much prospecting, however, will eventually run into locations where ground mineralization and hot rocks makes using a VLF such a challenge that a good ground balancing pulse induction detector is the only real option. The GPX 5000 represents the current state of the art, and is the easy option if money is no object. It is well designed for long hours of prospecting, has an incredible variety of optional coils, and can handle most any ground conditions with many tuning options. The Garrett ATX provides performance that comes close to the GPX at a much lower price, with the added benefit of being waterproof to ten feet. Actually, this is only a benefit if you need it. Otherwise it makes the detector heavier than need be and limits the available coil options. Still, if the GPX is not an option the ATX would be my next choice in a new detector with a warranty. For those needed waterproof it is the only real option along with its predecessor, the Garrett Infinium. The White's TDI is an older design but still very capable. It costs less than the other two options, and unlike the Garrett it has light weight versions and models that can be hip or chest mounted. It is a good option to explore for those on a budget or needing the most ergonomic solution. The TDI is also a very respected beach detector, like the ATX above, but it has no waterproof option.

Can it be done?