Search the Community

I did a coil test some time ago using a Tdi Pro OZ, quite a variety of coils involved. Just a bit of information not wanting it to go to waste. The test area was located in the middle of the Golden Triangle in Victoria, Australia. Looking at the images the test site is located on a area that produced large nuggets. Heavily mineralized to give the depth tests some authenticity. Targets were varied as were the coils tested. The Tdi Pro was ground balanced, gain was at 5, conductivity was in ALL, pulse delay was 10. Frequency was set in the middle and the audio was boosted by a Nokia MD-11 external speaker. Only clear repeatable signals were recorded. All targets were buried in the ground sideway from a miners hole, so as not disturb the soil on the surface or above the target. Only the 1 grain ingot and one 0.5 gram gold coin were buried from the surface disturbing the ground. Not sure how useful this is for Tdi SL users, deduct 10% maybe.. Just gives a sense of what is realistic is this one location at that one time with the Pro with the variety of coils available back then. All the best, Karelian

There seems to be much interest still on the TDI-SL mods that our friend Reginald Sniff made. I often find old emails in my junk box from people trying to get the mods. I apologize for not replying as I find them late and often busy with day chores. I will share what I still have left from my conversations with Reg many years ago. Most were over the phone as he had difficulty typing on the keyboard. I took notes and why I have the last picture with a summary of the three mods. Correspondence Reg, Thanks for the picture. I do have a few questions regarding my early model SL. 1- you had mentioned in another thread about doing something also with D20 and D21. We spoke only on changing C20, C21 and removing C56. What is the purpose of the D20,21 Mod? 2- Are C20,21 Polarized? what is the direction of flow ? ( thinking about building a board with a toggle switch to change from OEM to modified.} just in case the mod has an effect on my using my BIG coil. 3. If I did a board would the cables running from the capacitor board to the detector board need to be shielded? I just ordered the Reidman battery. Thanks Gilbert EMAIL sent by Reg in response: I mentioned mods added in 2015 to the SL to correct a problem in Australia. The mods to correct that problem included D20 and D21.. The D20 and D21 were part of that mod as was C56. You can remove D20 and short out D21 with a simple jumper to complete the Aussie mods. This will smooth out the ground balancing a little. If you use the proper caps, C20 and C21 are not polarized. Do not use polarized caps. I don't recommend a board to be added. Just tweak the Delay a little if the cap mod increases the sensitivity too much. On the latest pic I sent you, you will see an arrow pointing to C42. Adding a jumper across this cap will increase the gain and make very weak signals more reliable. Adding a jumper is easy. Simply look for two test points TP2 and TP31. They are near C42. Simply add a jumper from one test point to the other jumpers C42 and takes care of the problem. C42 and R75 are a high pass filter that isn't needed and causes problems. Eric added them when he had a drift problem and thought they would help. The drift was coming from some place else he later found out. Reg ( caps being removed are C20 &21, .47uf and will be replaced with .22uf. Use 50v Panasonic, or Rubicon Stacked Metal Film Polyester type ) from another post by Reg Picture sent by Reg My Summary of all three TDI-SL REG mods Gilbert

After reading CaliGold’s posts about his bad luck doing a battery mod on his TDI SL, I am so thankful that I put a TDI Pulse Scan/TDI Pro at the top of my list of wants if one happened to become available. I have only owned TDI SLs and the SPP both of which I battery modded to get more voltage and sensitivity/depth. Those TDI’’s even with the battery voltage increase always left me wanting for more. So, when snakejim’s TDI Pulse Scan modded by Reg Sniff went up for sale on this site I decided that I would try it and see if it was an improvement. All I can say is……Wow. The TDI Pulse Scan that snakejim sold me is amazing. I got a NF Sadie for it as soon as I realized its potential and sold the two Jimmy Sierra/Miner John coils that came with it since I have also always felt that those coils just didn’t measure up. It looked like this TDI with a Sadie might actually make a decent small sub gram gold nugget detector which is something I would have never tried with my previous TDI SL variants. The Sadie and Reg’s modifications did the trick and this TDI can easily equal and out perform my Deus 2 using its FMF Goldfield mode on .25 down to .05 gram nuggets. Very impressive. It’s not a GPX 6000 by any means but this Reg modded TDI Pulse Scan is no slouch with a Sadie. Also, I am so glad I don’t need to worry about doing battery mods and worry about my TDI being underpowered. I always assumed that the difference between a battery modded TDI SL and a normal TDI PulseScan/Pro was minimal. That is simply not the case with this Reg modded TDI Pulse Scan. Thanks Snakejim. I am going to hold onto this TDI and when it’s time to let it go due to my age, I will make sure it goes to a good home.

Is there anything that you can share on the details of getting the 16 volt battery configuration to fit in the TDI BH? I have one that I just bought, and I have heard that I can pickup a few inches of detecting depth with the 14.8v vs. 12 v stock config, and maybe even more depth with the 16v config. I would appreciate any details on whether you saw any harm to the electronics with this extra, applied battery voltage or not, the benefits of the higher voltages, and the needed case mods to make it fit? Thanks kindly. Brittany.

I built a 5 battery 20v pack for my whites TDI SL. Got info from this forum. I think I blew a resistor maybe more. No obvious visual damage but the detector behaves strangely now and signal is delayed on targets. If I put a target to the coil (miner john 8x12 stock) then the signal is delayed from sounding off for maybe 1/4 second or so. Odd... The miner john was handling the 19.8 volts fine but when I put the Coiltek 14" "TDI Series" coil on my troubles began. Wild threshold swings, wont pick up small targets (the 14" wasnt good with them anyhow) and now the MJ 8x12 has same delayed signal sound and struggles to pick up a 1.5 gram gold cross I used to test it with. The detector "works" it's just wonky and no use for prospecting now... Any help or thoughts greatly appreciated as well if anyone knows the wattage on the small 2512 size resistor at R9 area and around there I'd greatly appreciate the knowledge.. I've used the detector before in all areas it acted strangely in so please rule out EMI... I'm sort of in the country and it's relatively low signals around here despite the housing and especially in the river bed near my house. I think the Coiltek jacked up my PCB parts somehow. Thanks and have fun laughing at my rookie mistake!

I know there were a few greats in this field a while back Reg being one of them (RIP). But im looking for any info in the whites TDI mods and mabye some instructions. I have a big box I know a bit about the batery but more information would be appreciated. I really would like the stability mod or any others that you could give me. Thanks

Hi I buy a" whites pulse scan tdi pro "from ebay It has problem When it turn on and work for 40 min it cant sense any more(cant sense any metal). Treshold sound work like before but tdi cant sense any metal. I change battery pack and i test it again but it has no change and tdi cant sense after 30 or 40 min i should turn off tdi pro and after 40 to 60 min it can sense. maybe it warm and need to be cool Whats the problem? What should i do to solve this problem? Can i reinstall the program(firmware)? How? Thank you

I have tried for 4 years to find a true mono "oz" coil for my White's TDI. Had one guy sell me the 7 1/2" White's coils for an OZ coil but it turned out to be the White's TDI dual field coil according to one of the engineers that worked at White's. Some of the areas where I hunt have harsher ground than the red dirt in northern Virginia. This is man made issues because of the coal slack (that easily attracts to a magnet) discarded over many decades in these areas. The TDI has found many targets that the best VLF machines could only ID as iron.

I bought my TDI SL just as White's was closing. Due to other time commitments I have had only limited time to learn the machine. Reading various posts here and on other forums I realize that there are a lot of techniques that I need to learn, whether for gold, relics or coins. My primary interest is gold, but I occasionally search for relics and coins. I have tried searching this forum for information on techniques and videos but no luck. When I use the search term "TDI SL" I do not find any results. I have found just a few videos on YouTube. Any guidance on search terms, links to training videos here or elsewhere, or links to text on techniques would be greatly appreciated. I realize that I may have missed the obvious, and if that is the case, I apologize in advance. Thanks for the help.

Hi friends Im new member of this forum I want to buy whites tdi I know that i can use gpx coils for whites tdi for more depth, one of my friend had whites tdi he told me that its better than gpx5000, and has more depth sense than gpx 5000 He used 20" nugget finder for tdi 1.Which one is better? Gpx5000 or whites tdi? 2.Whats diffrents between these 3? "Whites tdi sl" or "whites tdi pro" or "whites spp" 3.Which one should i buy? 4.Where can i buy? Online shop or who sell Please anwer my questions and help me to buy Thank you very much

Hi, Someone who has the TDI Beach Hunter could tell me the value (color code and %) of the resistors behind the Gain and Volume potentiometer, and a photo of each please? Thanks.

I used during field testing.

Hi, my name is Alexander for reunion island. I am using a white's tdi beach hunter for a few weeks already. Very like it, my island is very mineralized, volcanic island and the tdi is working fine on it. This morning when I was diving with it about 2 meters deep, the sound change and it start to decrease. A few minutes later, I had no sound anymore, except a small creepy sound. I had to get out of water, 💦 and after a few minutes it start working again but when I am touching the volume know It's wet ✋ hands, the sounds change. Each time I touch it even lightly, just by contact, the sound change. It seems to me. That the potentiometer knob is dead. Is anyone of you can help me and tell me where I can find this can of potentiometer with his seal ? I do have the picture for it. Thanks to all of you for your kindness ❤️😊. I am very sorry for my English, I am a french speaker, English is not my best.

Hello, I'm new to this site, so bear with me if this question has been beat to death. I have a TDI Beach Hunter and I want to upgrade the battery pack, since the Whites packs are more or less extinct now. I was hoping to use the 3.7 V batteries (X3), but with how many mAh? I want to find one of these as well (see picture). Thank you very much! and happy hunting!

hello, can you tell me if a coil for a minelab gpx that can be adapted on a white's tdi beach. A large diameter like 21*17 inches or an 18 inch concentric disc for example. With a large disc we can achieve the depth performance of a fisher impulse aq, thank you all.

hi... so... i have a whites spp, and i know that the board is the same of the whites tdi sl. i have a oportunity to buy one whites tdi sl for 1000€, does it worth change from the whites spp to the whites tdi sl? i want to use the detector to find coins, objects, hoards, etc. thanks

Well that turbo charged gain mod Jim in Idaho wanted me to try out worked very well with giving me that extra depth I need to get those stubborn deep targets. I should have kept digging I think I could have made it to the Australian gold fields by the evening. 😂 Figured I’d give everyone a good laugh when I ran across that hole on the beach earlier today. Nice to poke a little fun!

I have a Pulse Scan TDI and would like to know on the connector that plugs in the machine, what is the positive (+) end of the plug, the ring (outside) or is it the center? Lastly, does anyone where I can get an electronic schematic for the TDI? Thank you, TC-AZ

Hi All, I'm new here. How does the TDI BeachHunter compare to the TDI SL? I'm in Vic, and am buying my first detector. I want a detector for the goldfields and occasionally the beach. TIA

Would like to know if any of you used this coil on a big box TDI? Trying to get some opinions and/or feedback. I heard that White's put it out for users who hunt for gold in Africa. How does it rate toward other TDI coils in comparison is my main concern? I just purchased a big box TDI and waiting for it at the end of week. Can hardly wait to use it! Would it be advantageous to get one or would I be stuck with a "lemon"? TC-AZ

Hello everyone — sorry I haven’t posted anything in the past when I originally signed up years ago. Maybe I did cannot remember. Unfortunately I have been fighting pancreatic & liver cancer for awhile, but I did have the Whipple procedure and it looks like the docs got it. I am in recovery mode now. They say I am part of a 1 percent club. Just started detecting again and trying to get back into swing of things with the forums n such. I will say it is great to detect again. Very glad to see everyone is keeping the TDI mods alive. I know Jim in Idaho — of course I haven’t talked to him in awhile unfortunately. I mainly use my TDI SL’s on the beach’s here in Florida (have 3). So if anyone is interested in performance of the machine with mods on the beaches just ask. The mods are not just for the prospecting side. If you have thought about the mods and haven’t done them — do them! They are not that hard to do on the SL. I might even have some extra matched caps if people can’t find what they need. I hope everyone is doing well in this crazy world and looking forward to posting. R/PI-Man (Gary)

A year full of distractions, so yes I kind of did forget about this project. All parts had been ordered and arrived in good time. Assembly to follow in the next few days... with photographs and a performance test on the modified Pro I still have.. I'll take it steady and do it right, get the soldering tidy and follow the plan..

A couple of recent posts referred to the whites TDI – so I thought I'd pass along the following. Last week I purchased a secondhand TDI from a guy who had sent it in to have Reg Sniff's noise reduction mod done - along with replacement of the op-amp. I had a TDI previously and the difference between that one and this one is like night and day. My old one had a warbly threshold that drove me nuts and made it very difficult to use the sensitivity higher than about 2/3 of full. My house is EMI hell, the neighborhood has underground utility service and the transformers sit on the ground. Even mildmannered VLF's like Whites Classics go nuts here at full sensitivity. This TDI has a silky smooth threshold with just an occasional blip at full sensitivity (12). It also air tests 17" on a nickle with the standard 12" DP coil! That's 4" more than I ever got with my old TDI here at the house with the same coil. I have been playing with the silver coin hunter trick with the high conductor mode selected and the GB offset to kill all ferrous. It really works - with the GB on 4, I hear no iron - and a quarter that I buried down 8" about 5 years ago gets a good signal with 2-3" air gap even using a 10" elliptical Coiltec mono. Now I need to find a dead Bigfoot coil and build a mono PI "Bigfoot". The mods were $125. Reg could probably furnish current details.

Hi, there. I was using my TDI BH for almost two years now. It worked great till the las week then I noticed an important sensitivity drop. In other words, the detector switches on and work as usual, but no matter what I do, I am getting less depth on my targets. Just to give you some numbers. My test target is a nickel coin which I was detecting from 27 cm a least (10us, gain full, gb off). Now, under the same conditions I can detect the same coin at 10-12 cm only. It is not the matter of the battery, as I have tested it with different batteries I have laying around. The TDI have a couple if weeks warranty left, but I have some doubts about my dealer's possibilities. On top of that the type of the fail is rare. Looks like the detector work as it should if not the lower detecting depth. For the person who is not familiar with TDI BH, this type of defect could be not so obvious. Any ideas what could be the reason? Thanks.

Does anyone have a copy of a circuit board diagram or a have a circuit board replacement for a TDI Beach Hunter? Does anyone repair Whites detectors? My control box leaked while water hunting in Fort Lauderdale and no longer works. It fried some components but I'm hoping it can be repaired. Thanks David