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Found 42 results

  1. Hi got a custom coil for whites TDI hand made in France by a top engineer ,i bought if for my deepstar but never used it. So whats more well this coil is the dog on the beach,less noises more stable and 2 to 4 inches deeper ,also a better ID of ferrous targets by a double bio easier to hear. The engineer is Alexandre Tartare owner of MANTA METAL DETECTORS Thanks RR
  2. Has anyone used them on their TDI and if so, how do they do on Gold? Especially interested in the larger coils like the 12"x15" mono for the GPX. Will it work on the TDI ? Would it be a good choice for covering a lot of ground prospecting for nuggets and will it find the smaller ones still? Would it be any better than the stock 12" dual field? Any experiences and help appreciated.
  3. Need mods done for my tdi. My sister has some property with an old township on it. Would like higher voltage batteries also. Can you put batteries in before mods or after? Thanks strider55
  4. To start with I must confess and hope the following information doesn't give the wrong impression about the TDI SL. It has a lot of potential, but only in certain locations not loaded with a lot of nails. I started inquiring about some old locations I hunt. Most of the locations are old, shut down schools where coal was used as a heating source for decades. Before the EPA was birthed most people did what ever pleased them when it came to disposing of waste, regardless of what it was and these old school sites are no exception. The burnt coal waste was spread over many acres of school property which created some extremely harsh ground conditions. Grass and weeds find it hard to get a start and most areas are void of any vegetation. Most of the school grounds look like Martian landscapes with small BB size or smaller pieces of coal waste everywhere. This material attracts to a magnet with little effort and can reduce depth of all VLF detectors by well over half. In fact until recently maximum detection depth was actually 2-3”, any target deeper would give a solid iron audio report if any sound at all. After many years of hunting these areas all but completely unsuccessfully I finally purchase a White’s TDI SL. It turned out the SL opened up these old sites and many nice coins and relics were unearthed, but not without many trials and numerous adjustments. Case in point: one particular area had been, in my opinion hunted out with many different VLF machines over a 10 year period and I was certain there were no good targets left. I had been hunting about 15 minutes and all the SL was giving were very short audio reports, which sounded more like chatter or EMI and not targets. This prompted me to increase the time delay to about 15 “which increases the time before a transmitted signal is analyzed” thinking the small pieces of coal waste were the short reports I was hearing. Continued hunting another 5 minutes and noticed the short audio chatter continued but not to the same magnitude. Stopping and increased the delay to around 17 and off I went hunting again. Suddenly I noticed the machine was running very quiet, to quiet. A minute or two later and a very loud low tone, which on the SL means a high conductor, I stopped and reduced the delay to 10 and found my definite answer. The coal waste was causing all the ground chatter and false audio reports. Increased the delay to 17 and recovered a wheat penny around 4” deep. Now to be honest I had to stop for a moment and think about what just happened. Decided to start over I returned to where I began hunting and discovered I had passed right over many good targets. After digging a few more wheat’s I decided to start checking these targets before digging and discovered if I decreased the delay most of these targets became the short sounding audio reports I had heard earlier. The PI was just the trick to discovering some nice coins deeper than 4” in these barren areas. I must add the SL is not the best choice to make if there is an over abundance of nails because of the very limited discrimination capabilities of this particular machine. As a final note I must admit this machine has opened up a lot of hunted out harsh ground sites.
  5. I recently added a PI unit to my weapons hoping to get further depth on caches of buried cans and bottles at 3 feet and deeper. I am mostly using the detector only to find the deeply buried pits of ferrous cans/ "trash". I know there is a learning curve to all new equipment but am throwing out some questions here for those who have used the White's SPP. First thing I notice is the detector is very sensitive especially to shallow scatter like concentrations of scattered nails and wire, especially wire in coils or even hangers bent in round loops sound like a much better target. I have read that adding a much larger coil like an SEF style in 20x17 format will eliminate some of the "noise" of semi surface items as well as add a bit of depth. My question is having the SPP without the Pulse Delay setting am I going to have a problem running these coils? I had read elsewhere that guys turn up the Delay setting when using the larger coil and the SPP does not have this ability. My first time out experimenting on finding a large deep target of cans I knew existed I ran the coil that came with the unit and in range on controls suggested in thres and gain. I picked up a number of small sharp high tone signals and dug them just for experience. I came up with bottle caps, loose change, a 2 dollar Mexican coin and a nice men's gold band. But these are not the type of targets I seek and would rather hear the deeper low tones that suggest concentrations of deeper buried metallic objects (trash). I was able to easily find the pit of old cans that were about 3 1/2 feet down but noticed it was very hard to pinpoint the signal and it seemed to overload or max out the detector signal. When switching to OFF on GB and running in an non motion mode I did well but experienced the same overload type effect on deep concentration target. When I turned the GAIN down some it helped with average targets of say 6 pack of cans at 2 foot, but I lost the ability to pick up the deep target. I know I am looking to use machine in ways most are trying to avoid in digging "trash" but just looking for any suggestions on coils and settings that may help with my learning curve. THANKS!
  6. Recent discovery of the conductivity switch on my White's TDI SL. The video shows what I've found. It also works the same with the 7 1/2" dual field coil. Just the opposite happens if you run the machine with the conductivity switch to high, low conductors are also heard. These results are the same as in ground targets to about 4" deep. More information to follow......
  7. Revisited the bad lands today. This time settings were a little different. Still a lot of nails in this area, but this time I opted to hear only low conductors and it paid off. One 10k GF and a nice 10k class ring. And of course the double handfuls of beer tabs, beaver tails and pencil erasers. All in all a pretty good hunt. Todays settings were: gain 6 GB 6 delay 18 low conductors
  8. Somethings going on w/ Salty;s choice of Machines Here! Nice piece at good depth. Y -Go Vlf???? over Zed's zvt?? Just wondering??
  9. Not trying to clog up the forum with ebay item(s), but this looks like a hard-to-find item someone here might want: Never seen one of these myself and have never heard of this company (if 'Cannon' is actually a company name -- maybe it's not). Says 17 microsecond or longer delay is recommended, which takes it out of my wheelhouse since my TDI/SPP is locked at 10 us.
  10. Want to buy a Whites TDI Pro. Require main control box in good working order. (I can still easily upgrade coils and shafts.) Only interested in a Pro, not a base TDI or TDI SL. PM me here best way to get in touch. thx
  11. After Reading many post about the TDI SL The Topics always Returned to the Issue about Batteries so I thought I would Buy A Few Dozen Batteries and put it to the Tests Because I think that most people are Holding Back or putting off buying a really Good Machine based on the Issue of the Batteries, So I am posting this in order to let people see that The problem is easily solved and is A lot Cheaper than you might think, HH I have done Tests with Batteries here's what I Got, 1) The Standard HD 2200mah NiMh Pack 4 hours 20 minutes 2) The Dry Cell Pack Fitted with 8 X 2650 mah NiMh AAs =(11.63 volts) 6 hours 37 minutes 3) Modified Dry Cell Pack to Fit 9 x 2700 mah NiMh AAs =(13.009 volts) 6 hours 38 minutes NOW IF YOU USE:- Righto If you use 2900 mah NiMh Batteries you should get Around 7 and A half to 8 Hours Run time, which is more than enough with out Taking A Break, So My Advise to All You Fellow TDI SL Brothers and Sisters, Is To Use the Dry Cell Pack with either 2650s, 2700s or 2900s As Your Main Pack and use your Standard HD 2200 Factory Pack As Your Backup, Using the 2650s and the 2700s works out 4 X Cheaper than Buying the RNB Pack. NOW YOU:- Now You might of noticed that I Modified the Dry Cell Pack To Except 9 X AA's, Why you might Ask??, Well many People have Claimed that By Increasing the Input Voltage That you would Get More Depth?? Well It Did To A Degree But it helps the Sensitivity more than depth because it is running at A Peak Voltage, Is it worth the $10.00s to buy an extra Battery and the Single Battery Holder, Maybe?? But for ease of Use I am Going back to using 8 X 2700+ Batteries, Although I was Running A Higher Voltage It did Not Give me more Run Time as I expected, Because when you increase the Input Voltage that has A Down Side, Because The TDIs will Consume more Amperage as with all things Do although that 13.00 volts does give you a Happy feeling Inside, If you are going to Carry Disposable Batteries then Only Use Energizer Lithium's as they have A Much higher Voltage than Duracell's and Normal Energizers at 1.61 Volts, Where AS The Energizer Lithium's Have 1.83 volts which @ 8 X 1.83 = 14.64 Volts, DON'T PANIC Because the TDI SL Can Run 16.00 Volts Safely, OK, NOW These Energizer Lithium's Have A 10 Year Shelf Life, and have Working Temperature of -40*c to + 40*c++, and they are the only Battery that Is Guaranteed Not To Leak, So If you Own ANYTHING of Value to YOU Only Use these Batteries In It and Even more So with your Detectors because The High Voltage Makes the Machine A Bit Deeper and A Little More Sensitive and A Longer Run Time than Normal Energizers or Duracell, Please Note That Duracell's work Better than the Normal Energizers because Duracell's power slowly goes down, Where as Normal Energizers stay Bright and then the Voltage suddenly drops Fast and if you are using them in a flash light/Torch Then Don't Be Surprized if you find your self in the Dark, Anyways I hope this Helps, John,
  12. I am curious what you guys think about the TDI SL. To start off - I KNOW it's not a GPZ! Price, weight, usability... it seems to have em covered as far as the under 1.5k pulse market goes. Maybe it's just under-marketed. Hope it's ok to ask here, I really appreciate what a resource this board has been for me in my first year at White's. I figure what better way to get an answer to a question than go straight to the folks who know best. So - let me know what you think about the ol' SL. Good. Bad. In-between. Open to suggestions.
  13. For those interested:,2334439
  14. Josh Bohmker helped us shoot this video for the TDI SL. He and his dad are refining a technique of hunting pocket gold down in Southern Oregon and I was able to join him and Dennis Dickson for a day trip. Afterwards we all hunted in the rain for a couple hours. Found an old stamp mill and the diggings but the cold rain seeped into our bones pretty quick. Did pan around the mill and managed some specks but we'll save the nuggets for the next trip down...dit
  15. I followed all the coin settings per Steve and others on the Internet ( high conductivity ,GB on 4 then 1.5, gain max, 10 s,) and she still sings on nails and everything else , I was getting signals on almost every swing, it was not silencing any iron like the videos by the southern fella, I am just going for coins where I have already hit with the mxt. Help please
  16. I decided to give a go at nugget hunting with a detector here in Ireland. I equipped the TDI with a new 6" Miner John coil and off I went. Third signal in and up popped this nugget. Not a monster by other countries standards but here in Ireland it is a monster. I am still buzzing and cant actually believe I found a nugget with a detector, but one this size, well over the moon is an under statement.
  17. Hey Guys, just a short video from a few weeks ago, in the video I quickly sweep over an area to clean off the surface targets so I can work the area later with the GMT, good example of using two cheaper gold detectors to your advantage. oh' don't watch it if your sensitive to swearing or dogs feeding themselfs. Enjoy, I'll post up another video later on.
  18. 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
  19. 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!
  20. 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"
  21. Does anyone have a vid link to a nugget going low-high (filmed after the update only) that shows how deep it was and how big the nugget was? On nuggets up to 40 grams I still cannot get a low-high signal with just one exception and that is squirrly little wiry or thin flaky pieces that flip between high-low and low-high, and with some regular pieces when they get really close to the coil they will flip between the two as well. I had a 65 gram slug of solid smelted gold and it was going high-low on the GPZ. It was low-high on my 45 though. What I'd really like to see are the types of gold that are low-high from beginning to end, no matter how far from the coil. If anyone has some links or has such a nugget and could toss it on the ground and film it I would be very grateful. One reason I'm wondering (ok, don your tinfoil hats) is low-high is so often iron now that I can't help but wonder if discrim might be possible with ZVT tech and there may be some kind of "discrimination update" coming in the future. Also, bonus question: can anyone show me a case where General is outperforming High Yield in depth and sensitivity and what exactly the type of gold (weight/sponginess/etc) is that causes such a thing to occur? Or ground type if that is causing the difference. We see it on the ML chart (or it would appear that way but we don't know for certain due to omission of actual sample defintion), but I haven't found a case with my gold where it happens yet so I'm curious what to look out for or if I should just give up on going back with General after HY unless I have gold past a certain size threshold.
  22. Today I sold a Whites TDI pro to a customer, we set it up and turned it on with the stock coil and did a few air tests. He heard that Minelab coils would work and other PI series coils. I suggested we try some Detech coils with the following results. The new 14in Mono Spiral wound ran quieter and air tested a little deeper on coins than the stock dual field. The little 6in Detech mono was a surprise as it hard and loud on targets for its size. When the weather gets better we are going to try a variety of the Detech coils and see which are worth having for the TDI, outdoors with more realistic buried targets. I`ll post what we find out.
  23. Can someone tell me who makes the Jimmy coils for JS? Thanx
  24. Well, thanks to forum member YubaJ I just ended up with a very slightly used White's Sierra Pulse Pro, or as it is more commonly referred to, the White's SPP. Bonus is it came with three coils, the standard 12" round mono, a 6" round mono that was part of an introductory special when they first came out, and a 5" x 9" Miner John folded mono coil. The Sierra Pulse Pro is nothing more than a White's TDI SL with the Conductivity switch and Pulse Delay knob both removed. The unit is locked into the hottest 10uS pulse delay. It is a limited availability machine only available from west coast dealers and in Australia. The whole story on how it came about is kind of interesting and detailed in my original thread on the machine from May 2014 at Now you may ask, why did I get this detector? There is a story there also. My first detector was a White's Coinmaster IV that I purchased in 1972. My first detector dealership was for White's in 1976, and I have had good success using many of their detectors. I currently have a White's V3i with Bigfoot coil that is my jewelry machine for large parks and sports fields. Bottom line is White's and I go way back. Whether I intend to use them myself or not I like spreading the word about on new models others might be interested in, so I perked up when the SPP was announced. I was more than anything just excited to see a ground balancing pulse induction machine introduced for under a grand, plus I always liked the ultra light weight of the previous TDI SL model. So I really was kind of pumped up to get one and posted on a few forums about it. Now, I used to hang out a lot on the White's Electronics forum at to just offer some free help and support as one of the only people there that seemed to know much about the White's GMT and TDI models. I made a post there identical to the one on this forum at the link above, and I get this message from the moderator: "Had to remove the Pic and "Sierra" name from the title of your post. The SPP is a Jimmy Sierra product, and as such isn't allowed to be "advertised" or "plugged" on the open forum." I posted again, something along the lines of "WTF it is made by White's and is sold by White's dealers but because it says "Sierra" in the actual name of the product I am being censored?". I got another message saying my "rant" had been deleted and the issue forwarded to the admin. That was it for me - I banned myself and have not participated there since. Jimmy Sierra later contacted me to apologize and he did set things straight with the people at the forum but water under the bridge by then. Just another example of the strange and convoluted politics at White's Electronics. I had been all fired up to get the SPP but just put the whole idea aside at that point. Yet down inside I still wanted one. So when by pure chance I saw this SPP for sale at a good price I pounced, purely as an impulse buy. I have no real use for the machine and will probably sell it but I want to play around with it a bit. The main thing about the White's TDI SL and the SPP is they are crazy light weight. The machine weighs about 3.5 lbs with the 12" coil and right at a perfectly balanced 3 lbs with the smaller coils. This is what the Garrett ATX or Minelab SDC 2300 could have been and should be packaged like. After swinging a GPZ 7000 all summer the SPP feels like a feather! Now, the TDI SL and SPP models are not high power pulse units and like the Garrett Infinium they really do not do any better in low mineral ground than a good VLF detector. However, as ground mineralization and hot rocks get worse there is a crossover point where the problems these conditions cause on a VLF (loss of depth, false signals) can be overcome by using a ground balancing pulse induction (GBPI) detector. Something many people do not understand is that by adding a ground balancing circuit to a PI some depth is lost in an absolute sense, and this is very easily illustrated with the TDI/SPP models in air tests by just turning the ground balance off. The machine gains quite a bit of extra punch, and a nice thing about the White's GBPI models is they have this ability to be run in pure PI mode in low mineral ground. In particular this makes the original TDI and TDI Pro models some of the best beach PI detectors you can get your hands on. In the case of the TDI SL and SPP however running the machines with ground balance off is almost the same as running a good VLF in all metal mode. The only difference is you do get the ability inherent in all PI detectors to ignore some ground conditions due to the pulse delay and how it works. See Understanding the PI Metal Detector by Reg Sniff for details. More about the SPP versus the TDI SL. The SL comes with what White's calls a Dual Field coil, which is basically a small mono running inside a large mono. The coils look like doughnuts, the outer rim being the large coil, and the inner circle being a smaller mono coil, both running at the same time. The theory is the depth of a large coil with the small gold sensitivity of a small coil, all at the same time. The problem was these coils were a bit too hot for Australia, and so the SPP coils are just regular mono coils. Easy to confuse also because a 12" Dual Field looks identical to the regular 12" mono. My unit has both the 12" mono and a 6" round mono that was part of an introductory special (now over). The SPP was a killer deal at introduction with two coils for $999.95. It is now being advertised new with a single 12" coil for $999.95 but is being offered by at least one dealer for $899.95 with the single coil. I really like the little 5" x 9" folded mono coil and scuff cover that came with my unit. What is a folded mono you ask? Something Reg Sniff came up with, details at,2051175,2051224#msg-2051224 Basically his answer to the White's Dual Field, which was patented. Miner John sells these for $199 at and it is probably one of the best coils you can get for a TDI to hunt gold. Finally, the SPP is interesting because it really is a TDI SL under the hood. The plug in connections for the Conductivity switch and Pulse Delay control knob are still on the circuit board, and the SPP can be upgraded back into a TDI SL for just a few dollars in parts. Here is a thread on adding the Conductivity switch back in at You can see the little white plastic sockets on the control board picture below marked conductivity and pulse delay. Anyway, just got this and no time yet to do more than take pictures and post but when I get time more will be forthcoming.
  25. Just with the Minelab PI coils being used on the TDI's. I've heard that once you get over about 14" with some coils the TDI's struggle to run them regardless of pulse delay settings etc? Was wondering if anyone has had any success with a larger coil on a TDI? Most, in Australia at least, seem to have success with smaller coils on the TDI series like NF Sadie & 12" x 7", 14" x 7/9" etc. Only ever heard of one being used with a 16" Coiltek but never seen or heard back any results with it, although I see one bloke said he tried one & then sold it going back to a Coiltek Blitz 14" x 9" which runs fine at 10uS. They seem to do well on small gold with the smaller coils here @ 10uS.Was wondering if this is why Miner John/Razorback are making coils specific to the TDI & Minelabs I.e. they have a 14" round for the TDI but it's not compatible with the Minelab PI's. They do however have other coils specifically for the Minelabs.