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Big idea from a bloke with no idea!!! Hoping that this forum can be of some assistance ? Well, with another trip to Western Australia done and dusted my last statement to my brother in law before I left was that "I don't think I will be back without a drag coil". Aaaaaaaand I am hoping to go back next year ? We did OK considering we were genuinely 'prospecting' and we knew that it may be a boom or bust type situation. The issue is that we passed over so much country because it is just too big. Vast. Expansive. And much of that vastness looks exactly the same - where the hell do you start? And of the patches we did find, then gridding out from those located pieces would be far more efficient and easier on the body than the side-to-side, slowly moving forward, small step action that gridding requires. I'll proceed with what I want to do, what I don't want to use, what I hope I can build and then questions re: what is actually feasible. I have looked through a few topics on here and there are snippets that can be picked up but not specifics and the cans, cants and have to's and how to's. I am really hoping to build a thread that anyone can follow and build their own basic coil design or at least have the basic idea of where to start. I'm hoping that @Reg Wilson @Chet @jrbeatty @Aureous @jasong @Geotech and others with technical expertise and prior experience can be helpful. Disclaimer - I checked out Geotech forum and although I am sure it is a fantastic forum I am sorry to say that it is all just too far over my head. I really need things in laymen's terms. I guess it is a case of if you never learnt it you just don't know it and I don't have the time to go and do a diploma in electronics. I help student/new nurses go through a step-by-step-by-step process of changing vacuum dressings on huge abdo wounds or changing PICC dressings or setting up a syringe driver for a palliative care patient. They are technical things and they need guidance, unfortunately I am asking for the same guidance here ? My basic plan - to make a 5 or 6 foot wide, oval or rectangle shape, mono coil that I can drag myself - not with a vehicle of any sort. My goal is coverage more than depth although depth is always a welcome advantage I suppose. I would be hoping such a coil could pick up shallow gold pieces that are 2 grams and up?? Mount the windings inside plastic tubing (inch poly??), solidify those windings inside the tubing with either some sort of foam or resin, affix that to the top of a folded piece of non-metal conveyor belt, place a solid timber on the front edge/folded edge of the belt and tow with a rope. All connected to a GPX series (4000/4500/5000) detector that can be carried on a harness with the battery, etc. As I am trying to keep-it-simple-stupid I am hoping that the windings can simply be bundle wound and that a gel type resin will both provide some weight, some rigidity and keep the windings in place. I do not want to use a vehicle due to the extra cost of purchasing a vehicle, transporting it and the EMI complications it can bring. As I will be pulling the device it needs to be reasonably light weight but not so light weight that it is not durable and that it does not remain as flat as possible. I know there is a pre-fab ready-to-go option with an @Coiltek 40 inch drag coil but I am wanting something a little wider to really make the process efficient. And I might learn something along the way ?‍? So before getting into the what I need and how to do it, I really need to start with 'Is it possible?'. Noting Reg's post below re: as things get bigger they develop more problems - is a 72 inch wide coil even feasible? Is this why Coiltek don't make anything over 40"? The build itself it adaptable but I am guessing the physics is not, so that is the first hurdle I need to over come. Question 1 - Will physics defeat me before I even start? Look forward to your responses ? Cheers, N.E.

I wish I had found this forum earlier. Just signed up today. This is best detector forum I have ever seen. I have an old GTAX 1000. Bought it new back in 2000. The factory coil (Crossfire Supreme Deepseeker) was destroyed in a car accident. The control head and top tube section were not touched. I home brewed a bottom tube and it works fine. I called Kellyco asking for a replacement coil. The sales person said they only had one coil that would work with a GTAX 1000. A week later I received from Kellyco a Garrett Pro Performance Elliptical search coil. I called Garrett to make sure the coil would work and was advised that it would. I purchased the new coil almost a year ago. I'm just now getting around to installing it. Here's the problem: The end connector on the new search coil cable will not fit the GTAX 1000 coil cable receptacle. Both cable connectors of the new and old search coils are five pin but of a different configuration. I can solder the old connector to the new detector coil cable. I'm just not sure of which pins of the old connector the new coil wires go to. Any help would be greatly appreciated. I have a new detector but I want to keep the old one because it has served my purpose for many years. Both Kellyco and Garrett detectors said the new coil will work with the GTAX 1000. I have attached photos of the two cable connectors. This is really a great forum. Earlier this afternoon I looked the forum over for over an hour. My old GTAX 1000 has found many civil war artifacts. I want to keep it alive. Thanks, Bruce in Kingston, OK

Advanced Metal Detectors Dr. Serkan Aksoy COIL (LOOP) ANTENNAS .......PDF Link...... ...... Part 2 ...... ...... Part 3 ...... https://abl.gtu.edu.tr/dosya/102/~saksoy/

Initially, I was considering experimenting with a drone with a hanging Deus coil. I still think it could be done but it would have to be specifically engineered for the task. It would have to be extremely stable and stay about two inches above the ground. There are very small drones that are that stable. Next, I considered a RC car pulling a coil on maybe a small rug. This experiment isn’t that expensive. I almost punched the button on ordering an RC car. Thinking it over, I realized it would fail due to trash. I still haven’t totally given up. New Idea. Coil in a plastic bowl so that it easily slides back and forth. The bowl is connected to the car with a small plastic pipe with a solid connection to the bowl. Connected to the car with a swivel, like a car pulling a trailer. The idea being, if you come across a good possibility, you can immediately stop and back up and do a little more investigation. If it sill sounds good, then you switch to the coil on the detector in hand. I don’t know if the controls are finite enough to do real short movements to check the target out. If you can’t use the rig to do quick further test, then it’s a bust because even in an open field there’s still a lot of random trash. This wouldn’t work in heavy trash but might work in large open fields. Interestingly, shortly after I abandoned the idea, this video was posted. As it turns out, the problem I realized on a small scale is a bigger problem on a bigger scale. Here's a video of an experiment with a really big coil being pulled by a PU.

As most know - the standard package deal in Australia was the 11x7" Mono and 13x11" DD-FC. The areas I detect are quite heavily mineralised soils, and at times the Mono has struggled with hot soils. I've done a few back to back checks vs a friend's 6000 and I found on the Mono that I wasn't able to detect some of the flatter alluvial pieces that the 6000 would get. Most of the gold here is definitely the smaller end of 0.5g. A few years into the Axiom existing - I'm now wondering if a 11x7" DD-FC with the ultra hot centre might be a good addition to the arsenal? it comes with a change in technique required and a lot of overlap, but I guess that's par for the course with small gold. Does anyone have any thoughts? Has anyone in Australia picked up the 11x7" DD-FC and found it better? I'm probably inspired by a post a long time back by @Steve Herschbach saying all the gold he found in Australia was actually with the DD-FC, and not the Mono.

These are now released and available on Ebay. 'Prospectre Coils' have 2 sizes right now, a 12x8 and an 8x6 in both an epoxy sealed 'All terrain' version and a lightweight standard version. Even the epoxy one is lighter than similar coils. Ive been trialing and evaluating these for some months now. These are standard bundle wound but are super quiet. Ive commonly run these at a gain of over 20-22 with barely a murmur. I got maybe 20 bits of gold with them (mostly the 8x6). They are 3D printed in PETG and so far, barely a scratch to them with over 100 hours of use combined. They say 'coming soon' is a 16x10 light weight and a 10x7 block wound version (which Im excited about). Very reasonable pricing too, the 12x8 is only AU$395!

The coil this guy is using is impressive- and goes deep on large items such as for irons. Does anyone know what it is and for what type of detector? It looks like a basic mono to me, just curious if it’s a VLF or PI and if anyone has done this? He also shows some impressive preparation skills for turning his finds into jewelry. (sorry - it’s just on Facebook but I’ll try to find him on YouTube as well) https://www.facebook.com/reel/9891757610904308?fs=e&s=TIeQ9V&fs=e&mibextid=wwXIfr&fs=e

Hi Folks, My detecting mate Joe and I have had the 10x5 Coiltek welded to the 6000 over the past couple of years. The standard 11” coil and the 14” DD have essentially been cupboard dwellers as they have not been the best option for us in the type of country that we scratch around in. When we initially purchased the detectors, the 11” monos were given a flogging and provided us with plenty of fun but the overgrown and difficult country that we play in had us tilt towards the smaller Coiltek nugget magnet. When something works well for you, to tend to stick to it. The bigger DD coil did find gold for us but it’s size and weight worked against it in the tight spots that we frequent. An opportunity for change hit us a couple of weeks ago. One spot that we have worked for years is located close to a small village known for its gold history. We have had a lot of fun scratching around in this area for bits and pieces but some spots have been basically undetectable due to emi and the overgrown bush. We have said for a long time that if the scrub was ever cleared, we’d give it a go with the DD coil. The zed hated this area as did any machine with a mono attached. About two weeks ago, Joe popped in after having a look at this place again. He said that the bush had been removed to reduce the fire risk and he had been out for the day covering the area with the DD bolted to the gpx. He showed me a couple of nice nuggets that he’d uncovered. Not the usual flyspecks that we tend to find but pieces that were actually visible to the naked eye. From memory, the first nugget was about .7g and the bigger piece was just under 2 grams. Anything over a gram is a rarity these days so these pieces put smiles on our dials. It was obvious that some further investigation was required. We headed out last week with the idea of covering the cleared ground before too many people had a chance to work it over. Someone had already been through and detected this spot and had left evidence of their work. It was a shame that they didn’t fill their holes and make an effort to leave the area as they had found it. The DD coils ran really well. Emi wasn’t an issue and we were able to concentrate on even the smallest change in the threshold without having to listen through a constant whine in the background. As you would expect, there was plenty of junk. Bits of lead and .22 shorts were common with many of them excavated from considerable depth. I was running sensitivity 10 in difficult and for most of the time the six purred like a kitten. We worked for two or three hours without any luck until I picked up a really faint signal. It was a bit like one of those broad ground noises that you sometimes get and it was barely audible. As you do, a bit of a scratch with the pick was performed to confirm one way or another what was going on. The soil was black and unconvincing but the sound was still there. A couple of inches of soil later and the machine had come to life. It was a repeatable signal and sound was as mellow as a 14 year old Scotch. Joe was about 30m away and I called him over. We quite often share these moments as we both get excited at the prospect of uncovering a piece of gold. Disappointment is often on the cards but this time, I was feeling quietly confident. Joe started digging with the pick and as the hole deepened, we hit some orange clay. This got us a bit more excited as the chances of finding rubbish had diminished. The signal remained sweet and didn’t take on that offensive scream that often develops. Pinpointing with the DD takes a bit more work and during the excitement of the dig, we started scratching in the wrong section of the hole. After an adjustment, the target finally popped out of the hole. When Joe eventually spotted it in the scoop he exclaimed “I can see gold everywhere”. It was an exaggeration of course but I was very happy to eventually hold a nice nugget. We were now fired up and ready to go. There had to be more…… It was only a short time later that Joe called me over. He had a beautiful sweet signal that had developed after digging down a couple of inches. When I started attacking the spot with the pick, beautiful gravels started to appear. The soil profile again changed with quartz and a mustard coloured clay being dragged out of the hole. Again, the indicators looked promising. As with the previous target, the signal remained smooth and our anticipation grew. When it finally appeared in the scoop, I couldn’t believe what I was looking at. It was another nice solid little chunk of gold. We couldn’t believe our luck. Two better quality pieces of gold in the one day just doesn’t happen in our local area. This is a memory that Joe and I will savour and look back on with a smile for many years to come. Without the DD coil, this day would not have been possible.

Rumor mill sounding off on possible new coil for older model GPX, is it true?

Here is my very well taken care of Bigfoot for DFX - MXT serial #914. It is 17-3/4" x 3-1/4" x 1" and weighs exactly 12 oz (no scuff cover) This is a later model; the earlier ones were thicker and more rounded in profile (see sales brochure below). Following that is a scanned/ocr copy of the hard to find instructions that came with these coils. JIMMY SIERRA BIGFOOT OPERATING INSTRUCTIONS DFX/MXT This NEW Bigfoot coil is a completely new concept, designed especially for the DFX. It is not shaped differently JUST to LOOK high tech. IT IS HIGH TECH! This particular shape is necessary to house a coil design known as differential geometry. This design has two goals. First to cancel the effect of much of the ground mineralization before it gets to the detector and secondly to cover a large area of ground in one sweep from tip to tip for the full 18 inches of the coil length, much like a windshield wiper. An added bonus is that it helps to reduce 60 cycle interference, such as transformers and power lines. The BIGFOOT is 18 inches long and 3 1/2 inches wide. The DFX Bigfoot will work on the New MXT, but in a unique fashion. The Bigfoot on the MXT will produce a single beep on the front half of the coil and either a double or a wide beep on the rear half of the coil when passing over a target. In addition, it may read about 2 numbers higher on certain targets, which can skew the Icons (eg quarter to read half-dollar). The front half of the loop should be used when trying to identify targets on the MXT, as it is more dependable. Even though the MXT tracks the ground automatically while searching, do not forget to ground balance initially by pump-the the coil up and down a couple of times with the tip of the coil on the ground at a 45 degree angle as noted in the last paragraph below, with Track toggle set to GND. After that you can either leave tracking ON or set toggle to LOCK. I prefer to lock tracking off except in heavy mineralization. While the detector is operating in the GEB DISC (motion mode) the BIGFOOT detecting targets across the entire 18 inches of coil. When the detector is operating in the GEB all metal (non-motion) mode, the BIGFOOT is detecting targets ONLY on the front half (9 inches) of the searchcoil. Unlike the Spectrum & XLT, the DFX does NOT require the use of "Absolute Value" as the DFX only detects on the front half in the all metal mode, such as when in the Prospecting Mode. Pinpointing with the BIGFOOT is very simple and accurate. Squeezing the pinpoint trigger on the detector will make the BIGFOOT go blank (negative) on the back half (9 inches) of the coil. The front half of the BIGFOOT remains sensitive (positive). In other words, the target will only be heard under the front half of the coil. The trick, then, is to center the target by moving the coil from side to side till is seems to be midway from either edge and then squeeze the pinpoint trigger and push the coil forward like on a shuffleboard. The target will disappear as it leaves the midsection of the coil (marked by the two arrows) Thus by pushing the coil forward and backward you can easily hear the sound of the target appear (when it is under the front part of the coil) and disappear (when it is under the rear half of the coil) That point where it appears and disappears is exactly at the center of the coil between the arrows. The rear half of the coil is actually rejecting the target and so you hear a very distinct sound when the coil is pushed forward and the front half leaves the target. You might note that the coil is first moved side to side to center the target between the side edges of the coil, much like with a round coil and after it is centered, squeeze the trigger and posh the coil forward. Of course, if no target is heard when the pinpoint trigger is squeezed, the target is probably under the back half of the coil and being rejected. You should then just pull the coil backward a bit to get the target under the front half where it will be detected and then push and pull as described. Some users prefer to pinpoint right off of the front of the coil. This is OK, but I prefer to use the above method as it is more precise and very fast and easy once you get used to it IMPORTANT: You may AIR BALANCE the BIGFOOT the same as any coil, with the Bigfoot held in the air....HOWEVER, you MUST GROUND BALANCE the detector with the BIGFOOT pointed at the ground at about a 45 degree angle , with the FRONT tip of the coil touching or just above the ground and the REAR of the coil held OFF the ground at 45 degrees, You will then lower the coil parallel to the ground for searching as with a standard coil. It is, of course, best to keep the front and rear halves of the coil as close to parallel to the ground as possible. Use shorter strokes in trashy areas and broader strokes for covering larger, cleaner areas. If at any time, the Bigfoot appears to loosen up on the rod and wants to tip or paddle, it is time to either clean or replace the rubber washers where the rod joins the coil. The nut should only be tightened "finger tight".

Hey all, I just found my coil connection sheared off at the control housing. (oops, and bad timing as I was just headed out!) Luckily no damage to the control housing connection but the other end was bent and broken right off... I sent some photos to minelab to asses if they will fix it or not but still waiting. I was wondering if anyone knows if its possible to buy this connector anywhere? If minelab wont fix it then I will end up splicing one on myself and hope for the best (minus the water tightness of course) . Any help would be so appreciated!

I was trying to figure it out, hell I have no clue.. when I use it on the V3i I can run the RX to 15 and sensitivity to 90 with no problem, really quite .. But the nickels ID in the 50s, at least in 3 frequency…I put it on my M6 tho and it rocks, ID for a nickel is 18-20 and all other coins ID correctly too…thing just kills mid conductors at depth on the M6,,But is it a DD or concentric,the Bigfoot coil? I’m in western Pennsylvania, not mild but not real mineralized either, just old coal ashes occasionally..Seems to get the depth of a DD here,,concentric coils usually don’t do as well it seems in my area for depth.

COILS: Small v's BIG Coils. This was the day I was using a BIG COIL. My friend was behind me with an 11" DD He asked if I checked the tree that I just passed by. I stated my COIL was TOO BIG to fit inside the HOLLOW of the tree so my mate detected it. This 12 oz nugget was hidden inside the STUMP of the TREE. The Moral of the story is BIG isn't always better especially when you miss nuggets like these.

Over the years I've had several old sd detectors and collected a batch of coils. These 2 + the 18" garbage can lid. The ones in the photo are 8" and 10 1/2". They are not marked mono or dd. How can you tell what they are?

Fisher / Teknetics 2018 Coil Compatibility Chart Official Fisher Search Coil Page Official Teknetics Search Coil Page

If you talk with a gold prospector, saying about a gold chain as the hardest item to uncover, it is a joke. In my still modest 20+ years experience, I found no more than 12 or so. Every time cause of a pendant still there in the same hole, or at least an eye visible piece. Long story short, I found at some depth (2" more or less) one little pendant with a weight of only 0.32 gram. I know, the shape can do miracles in terms of response to the coil, but hey...With the M9 this opened my eyes and that's the reason for the title. There will be no more progress on a Vlf to avoid salt and listen to chains. I'm sure now. Still today, smaller items barely covered in sand can be reached but forget about decent depth perception of it, not underwater. The low conductors program performs to a limit where I can barely realize if I'm running way hot at 22 or something reacts for real to the coil. Wrong program underwater, wrong approach to the usual work, I know. Using different settings and programs will only get You a blind machine like many others on micro targets. Steve explained long ago the "salt against chains ratio" and now, again I crashed my nose on it. For peace of mind, I'm considering to stay for some time with a pulse machine and forget micro targets for a while... I think that I've been lucky enough to push the Manticore to the limit underwater in salt. Skull

I watched a test on a test-bed where a 2oz lump of lead was detected at its max depth with BOTH the stock 14 DOD and the 19 DOD. Same depth, same settings, same signal strength, the 19 provided absolutely zero benefit. The owners played with it for hours on 2 detectors....then gave it back to the Gold Center in Maryborough. None of the 5 Zed owners present, bought one. Not saying that the coil wouldn't have some benefits on bigger targets or worse/better ground conditions, but that day's 'presentation' didn't sell any....

Let's say I'm getting a gpx 5000 / 4500 and going to use it in the Victorian gold feilds (Australia) What coils would you recommend to have to cover most situations. Thanks in advance Roy

Huge Tesoro Vintage coil my friend gave me attached to another Conquistador. Nice. George.

I recently bought a GP3000 which came with a few coils. When winding them around the detector shaft the outer cable started peeling off. I've got some dual-walled heat shrink that I was going to apply, but I'm not sure about the white paper that has also peeled off in some areas. Any suggestions about what that white tape is? Or what I could use in place of it? The coil has barely been used but I assume storage wasn't the best as my 2200d and its coils are older and the cables are still in good nick. There is a possibility that the internals of the coil have dried out and the windings move, causing noise but I'll attempt to fix the cable first and see if it works first.

Is the Coiltek 14" DD waterproof? I know my 6" Coiltek is waterproof as I've used it in 2 feet of water. The other coils in the photo are 8" and 11" Super Goldsearch coils, are they waterproof? They are old so that worries me somewhat. What happens if a coil was to let water in? Would it kill the machine? I have had a coil in the past signal coil overload before when the grass was wet, but fully submerged is something else I presume.

I was wondering what you serious “Water” hunters use to weigh down your coils. Someone once suggested taking a “tube” sock, filling it with sand, tying it in a circle (like an ankle weight) and sliding in over your lower rod having it lay on the coil. I’ve also seen bandanas (to keep you cool) with Silica Gel sewed in to them. They absorb the water and expand making them heavier than they are dry. I wonder if you had enough in there, would that work also? Thanks!

Something I have wondered for some years now and have never asked, especially as there has been close to a 4 years hiatus for me in getting out and detecting- Is there a correct way to store a metal detector coil? Laying Flat maybe? Hung up on the wall on a hook or nail? leaning against a wall, left on a detector etc.,?..... On various forums and in different photos over the years I have seen them stored in all of the above ways, which also makes me think that perhaps it doesn't really matter either way? Also, with the exception of my Detech 32" CC I have simply left the small DD & Mono coils that came with the 5000 sitting flat in a cupboard. The Detech has its own foam-lined hard Pelican case, but do I risk warping/ affecting a large coils operation if I leave say my NF 25"DDX coil leaning up against a wall? There is no other option for leaving larger coils laying flat where we are currently living without risking them getting damaged. Thanks in advance, -Gary

I'm recently short of time to search, but almost sure there's still no trace of a 10x5 for the Manticore. Even if really satisfied by the 8x5, trust me, the exact same 10x5 for the Nox will be my last Coil when this happens! @Coiltek Do the miracle please...

I recently purchased the excellent LG 24 coil for the Legend for under $130. Why are similar sized coils by Coiltek (Equinox)and Minelab (Manticore) coils twice that price? Are they twice as good? lol