How good is your detector coil?

[00:00:00]Good day, guys. I was just doing some coil experiments and I thought that I might as well make a video about uh some of the uh results because they're quite uh interesting.

[00:00:14]Have a look on the oscilloscope there. I suppose you can see that that's the um signal generator there generating a signal into the coil via a 47 k ohm resistor.

[00:00:33]And basically what we're looking at is the load the coil puts across the signal via the resistor.

[00:00:43]And when we change the frequency and it hits the selfress resonant frequency of the coil where it's uh most efficient uh at a given frequency we can see the amplitude on the oscilloscope. But what I'm going to do and it's quite interesting. We're going to see how the Elite Coil here compares Oh, if I can ever get it off the floor.

[00:01:17]A really old Super Gold Search mono coil. Okay. And this thing uh yeah, it's seen better days, but uh we're going to check it and just see how it compares against the uh Core Techch Elite.

[00:01:39]And there's some things you can tell about this.

[00:01:44]the internal structure of the uh windings, the shield, the coil cable, it all tells a story. And put it all together and you can work out how good your coil is.

[00:01:59]um the geometry as in the shape of the coil. A round one should be better than an elliptical one because an elliptical coil soon as you start squashing that round shape. So like this it causes field cancellation and it should um actually affect the queue of the coil. The queue means how good the coil works overall.

[00:02:28]Q very interesting uh it stands for quality factor uh and uh we use it in electronics all the time for tuned circuits and things but anyway that's what these are these are tuned circuits uh resistance inductance and capacitance even the coil cable has capacitance you have capacitance between the coil bundle and the shield and you have each winding to the next winding and all the other windings as inter winding capacitance too. That will change the self-ress resonant frequency of the coil or of the whole thing. So, what we're going to do, how about for starters, this is only running about 5 volts out or so, so it's not going to zap me, but I'll show you how to hook it up. It's really easy and I'll give you the reasons.

[00:03:25]It's just a little bit of cable.

[00:03:28]I'll unhook it which goes onto the signal generator.

[00:03:35]Now the signal generator output on this particular one is 50 ohms. Not that you need to know that, but we need to isolate that 50 ohms from the coil because it'll interact and it'll pull it pull it down actually pull down the self-ressonant frequency. So, if you have a look here on the coil plug, sorry, it's a Jcar one, so I've goldplated, right? Okay. If you can see how I've h connected it. This is that pin there up the top in the gap is the ground pin and that goes to the outer braid part of this uh small coaxial type cable.

[00:04:19]And the next connector uh pin goes to a 47k resistor.

[00:04:28]It's pretty simple. And that goes onto the inner of this which goes to the signal generator. So it's pretty basic.

[00:04:37]And the coil plugs into that.

[00:04:40]Then we have the oscilloscope lead which uh if you want to get rid of uh a lot of effects put it on 10 times. These probes can have you know 50 odd pickarads of capacitance.

[00:04:59]Uh so we go to 10 times and that will drop to about 10 to 15 pickarads. it will make the reading more accurate within reason two that resistor the higher it is the greater you'll see the peak um of the self-ress resonant frequency uh 100k is probably better I just found a 47 on the bench and I used it so we're going to hook this up again I'm going to put this on the coiltech Elite max and we'll see.

[00:05:36]Should go back to exactly where it was.

[00:05:38]Upside down. There we go.

[00:05:41]Get this here. Short leads.

[00:05:45]Put this one on the G. That's hard. That one.

[00:05:51]Oh, dried out plastic. And this connector here goes on the resistor.

[00:06:01]No, you're doing that wrong. Connected to the coil.

[00:06:07]So, that's there. And we'll get this and we'll plug it in to the signal generator. I don't need this at the moment. I put on the chair.

[00:06:16]No, I'm not. I'll put it down there cuz I've got it sitting under that.

[00:06:27]Okay. And that's what I put it on 10 times, didn't I? So, I've got to lower this down.

[00:06:37]Okay. Suppose you can see that. Now, I've got this generator um at at the moment it's 506 kHz, which is quite high, half a megahertz. So, what I do, I adjust the frequency only.

[00:06:57]And that waveform there, I try and get it as big as possible. So, I'm going to do that right now.

[00:07:10]Okay, I'm gone a little bit low.

[00:07:15]Maybe one more. There we go. That lines up.

[00:07:21]Okay.

[00:07:29]So the self-ressonant frequency of the uh coil tech elite coil sitting there is 655 kHz. That's where it self resonant frequency is. The other thing we'll take note of as well is the amplitude, the peaks on the top and on the bottom.

[00:07:53]And we'll put the cursor line there so we have a reference. And we'll try the old Dunga Mine Lab coil from um probably a few decades ago.

[00:08:06]So I'll just uh line this up there and there. So we got our cursor lines set up on the peaks and the troughs. And uh so we'll know basically 655 and where it lands is as a reference on that coil tech coil. Now what we'll do, we'll take this off and I'll get this one and I'll put it down here. You probably notice even if I move it around, it has very little minimal effect on the coil itself. Even if I got this big piece of alloy and put on the coil, you have a look there at the um oscilloscope, this D-tunes and uh really upsets the coil and uh you can uh make it move. But I had to use this. Uh if you put it on the ground, even pretty highly mineralized ground, it's not going to do anything.

[00:09:07]You won't well basically it will do something but you won't be able to measure it. It'll be very very small. So we'll get that coil on the ground. We'll get this mono. You can see it there. The mono. You can see everything there. And what I'll do hang on a sec. You want to see everything.

[00:09:27]Here we go. I'll pull this one off and I'll put it on this one.

[00:09:40]Yeah, I got to get it lined up.

[00:09:42]No, it's the wrong way. And I'll twist that round like that. There we go. And let's have a look at this. There is a difference there. Just make sure all this is in the right spot.

[00:09:58]Yeah. On a downward angle, it wants to fall out. So, I just do it up a bit.

[00:10:06]Make sure everything's tight.

[00:10:08]So, after wiggling it around, there's a little bit of movement there, but uh we're all set up, ready to roll. And uh yeah, the um old Mine Lab coil has less peak amplitude, but are we on its self-ressonant frequency? It's a different coil, different winding and uh different cable, different little bits of differences everywhere. So, what I'm going to do now, I'm going to go and sweep the frequency, and we're going to see if that peaks up and is it a higher or lower self-ressonant frequency.

[00:10:59]And the answer will be, I'll find out in a minute. It'll tell the story. So, we're at 655.

[00:11:17]>> [clears throat] >> Now the Mine Lab coil even though it's an old we we call it an old dunger because it's it has been around the traps and uh yeah right there's nothing wrong with these coil gods.

[00:11:38]Now I'm saying that there is a factor of coil geometry uh and uh soon as you go from a round circle into any other weirdo shape elliptical, you're going to lose efficiencies. You just do. People think it uh will work the same. It won't. It's a drop off in efficiency. Um but there is a improvement in getting in tight spots, right? So with with the um elliptical, you still got more or less a cone shape, but it's a longer cone, but the round one is more of a proper cone.

[00:12:16]So there's trade-offs. The theoretically speaking, the round coil will always go deeper. Always. As long as the target uh has uh got some sort of energy going, it's going to register. Um, if you got a um, this this where it gets very interesting in the geometrics of it all.

[00:12:42]If you get a piece of gold and it's long and it's very similar shape to your elliptical coil, you can get a better signal from the elliptical coil on that because it has a better um, pattern which is replicating what the target is. If the target's like that and the pattern's like that, it's going to get a lot of energy into it.

[00:13:04]you're going to get a better signal where the cone is just going to come down to a point, right? And if that point is just touching on the target here, uh it's missing here, here, and here, and here, and it's not going to give a very good signal. It's still going to get some signal. Won't be very loud. If you can illuminate the whole thing, it's going to give a screaming signal. So, uh the thing is that uh normally if you're doing coil against coil for the same size elliptical and round the uh cone shape will go deeper on the round coil, but also it won't be on the point. It's going to be further up in here. So, you're going to get more um bang for your buck on a big deep one with a round coil anyway. In most cases, um, the elliptical one won't go as deep.

[00:13:56]You know, you'll be getting that far with the elliptical, but it'll be a a flatter type of, uh, pattern where the other one goes deeper, but it's a cone.

[00:14:05]But if it's at the tip of the cone, the small piece of gold here, uh, could register where this one here won't hear it. The elliptical won't hear it. So, normally the gold, if you're picking it up here, well, the cone here is going to be like that. It's going to cover it just as well. and possibly in some circumstances depending on the shape of the target. If it's a long skinny thing, you might get more out of the elliptical and uh if it's a round target like a a round uh you know knobbyby of gold, you're probably going to get a better target out of the round coil. So there's no free lunches with coils. Anyway, what have we got? [clears throat] According according to our measurements, the Mine Lab coil has a higher self resonance at 667 kHz.

[00:15:01]There's not much in it. Only few [clears throat] kilhertz in it uh for peak, but I can tell there's a slight very slight increase in amplitude, which tells me, you're not going to like this, that the Mine Lab coil is more efficient. It has a higher Q. Now high higher frequency and also higher amplitude uh is higher Q. So but it's probably based on the round shape. Do I have I have a Nugget Finder 12 in around somewhere which is pretty close to 11. It would read roughly the same. It's all muchness but I I don't Hang on a sec.

[00:15:54]Uh, you know, I play around with coils and do lots of testing on them, but I've got it here somewhere.

[00:16:10]I've got the remains of one. Um, there's a reason why this is in bits and it's to do with uh construction. I was just examining this is I did this years ago anyway. I'm not going to make too much uh comment about it. It is what it is.

[00:16:30]And we'll just have a look.

[00:16:35]We'll see if uh the Nugget Finder beats the old Mine Lab.

[00:16:40]So, stuff everywhere. Get down there. Don't pull everything off the bench.

[00:16:50]Of course, it's going to do that.

[00:16:56]Now, I must say that uh I've put uh another cable on this one for whatever reason. I don't know why, but we'll stick that up there. Oops.

[00:17:08]Now, I haven't even got I haven't got the uh earth connected to the outer braid. So, that's going to cause um a higher self-ressonant frequency because it's going to have less loading from the uh graphite shielding. Uh anyway, let's get this back up here around that way and around there.

[00:17:35]And uh we have nothing to see.

[00:17:45]You should have something. Oh, there it is.

[00:17:48]Hang on a sec.

[00:17:51]It's just the oscilloscope set a lock.

[00:17:54]And uh this has gone to pot.

[00:18:06]That doesn't look very good. Hang on a second. What's going on here?

[00:18:11]Uh, it's like it's being it's like it's shortcircuited or something.

[00:18:23]It's not.

[00:18:30]Even though I haven't got the uh outer on it, it can't be that bad. I mean, it's definitely not that bad.

[00:18:36]Believe me, something funny is going on here.

[00:18:41]That's one times. That's 10. It's actually connected.

[00:18:50]Hang on a second. Let's get a bit of metal. I'm just going to uh short the coil out.

[00:18:56]Well, that's connected. Um I short this end.

[00:19:02]It's connected.

[00:19:04]It's interesting. Obviously, uh, without the braid connected, it's got a crazy crazy very high self-ressonant frequency. I've got to fix that. Um, uh, I got to find some sort of wire I can connect up the braid to the shielding cuz I think that's what the issue is.

[00:19:26]Let's have a look.

[00:19:31]Famous last words. It's not okay.

[00:19:42]makes no difference when I connect the braid to the shielding.

[00:19:46]Don't panic. The these it's it's not as it seems. Uh if if it was like this call wouldn't work in the field at all. It'd be diffic. So something funny is going on.

[00:19:59]What can it be? It's connected. It's on.

[00:20:02]Hasn't fallen off. hasn't gone capacitively coupled or anything. No.

[00:20:08]Um, that's just me dropping the um the lead off and it's picking up my finger and anything else around the place. So, okay, I'm bamboozled. Um, it's just a coil.

[00:20:30]It's just a coil.

[00:20:33]You just I'll muck around the uh You got to be kidding me.

[00:20:49]The self-ressonant frequency of this coil is 520 kHz.

[00:20:59]The others are 665 and 667.

[00:21:03]It's a round coil.

[00:21:13]Amplitude's good.

[00:21:16]But why is a self-ressonant frequency so damn low?

[00:21:21]And remember, self- resonance and amplitude measurements theoretically equal the Q factor.

[00:21:35]I'm bamboozled.

[00:21:39]There's some something going on here.

[00:21:42]There's something going on. I wish I could I had time. I actually dug deeper on this a long time ago, too. I didn't I just used it as is. I never measured it.

[00:21:50]Uh I I measured the inductance of it.

[00:21:52]The inductance I think these are about 280 or something to it. Somewhere around there. 280 290 not 300 like a lot of coils. Um whatever. Um now it's funny when you make coils you get up to around the target value and you go, "Oh, I'll just put, you know, I'll get down to say um 280 or 290." And you say, "I'll bring it up 300. I'll put one more turn on it." And uh you do that, it goes to 340, right? Because um it it squares on itself. Uh and you you can't have your cable come in and have the you know say, "Oh, I'll put a half a turn on." Now, how you going to connect half a turn over here? You got to ether go right around back here or take the turn off.

[00:22:39]You can't have partial turns. Um because hanging it it's makes it very very um crazy and uh it'll probably pick up noise and all sorts of things. Uh it would be a real nutty type of coil. You got to have the start and the finish come back very close to each other. You can have a little bit of room there but not half the coil diameter. So um what's going on there? Um it is what it is folks.

[00:23:11]So, of all the coils, um, the one I'd say is the most sensitive is this, but it it's I'm putting it against a geometrically compromised coil, which an elliptical co coil for a solenoid type coil, which these basically are. um suji squash the shape in or whatever you do it's it starts um affecting the coil and the coil doesn't like it. Coils want to operate as a round coil for maximum efficiency. They don't want to have their side squashed in. Okay. Have you ever seen an electromagnet electromagnet at the uh wrecking yard with a uh elliptical coil? No. Either have I. um because there's a reason for it that a round coil works better uh it generates stronger more efficient field lines. So that's that. now. Um, I have made mention of this.

[00:24:28]I made mention about something about coils probably 10 or 15 years ago in one of the videos. And uh this could be possibly I'm thinking I suspect I've just realized more than likely what it is.

[00:25:01]And if I say too much, everyone is going to get a free lunch.

[00:25:11]So, we'll just leave it there. So, there you go, guys. That's a Nugget Finder coil with um um a big drop in uh I'm not saying it's a bad coil. This one, for some reason, uh the queue is um completely um down the gurgler. Um, I could uh hang on a second. You know what I'll do?

[00:25:38]This makes life easy if I do this. So, just do things on the fly. What I'll do, I'll just measure um the inductance on the LCR meter and I'll measure the queue as well because I can uh do that automatically. So, what I need is I need for this to come alive turned off because uh these have got accelerometers in them and uh if you um wiggle it around it turns on. They're good saving. Uh so, I'll just drop the resistor off. We don't want that.

[00:26:12]I'll drop the cable off.

[00:26:15]What I'll do, the old LCR meter. There's LCR meters and there's LCR meters. This one here, I got this. Um, oh god, so so old, but it's so damn good. Actually works really well. U, it also does capacitance. Uh, and it'll do capacitance down to a pick a parad or so. So, uh, I'll just plug it in on the on the coil connector and let's see what the queue is on this. So, uh, bear with me. I'll turn it on. I'm going to change the frequency on this. Uh, it's already changed for me. Thank you. Uh, and it's already on inductance. So, I'll stick it in there.

[00:26:58]If you can see that.

[00:27:00]There you go. I think maybe there you go. 291. I wasn't uh wrong with my guess.

[00:27:09]And the Q.

[00:27:13]Don't wiggle around. Let me have a look.

[00:27:17]wiggling around and getting off the terminals there.

[00:27:21]Have a look.

[00:27:23]This is going to be interesting.

[00:27:27]Come on. There we go.

[00:27:32]Let it settle.

[00:27:35]4.6.

[00:27:39]So that's a that's a reference there.

[00:27:41]4.6 on the Nugget Finder. Let's have a look at the queue on this and plug it in.

[00:27:56]God, there we go. So, you can tell a lot about coils just using test equipment.

[00:28:01]You don't have to go out in the field and go over targets and see how well they work. Um, your electrical measurements will tell you how well it's going to work. If you got a reference, you got to compare it against something.

[00:28:12]So, okay. And see how this one reads up.

[00:28:20]Okay, we're on.

[00:28:27]Okay, it's obvious. Look at the queue. The queue on this. Hang on. I'm wiggling it around again. Soon as I'm Hang on, I fell off the terminals. Hang on.

[00:28:58]Let it settle.

[00:29:01]Yeah. Q on the uh coil tech is 5.7.

[00:29:08]And I fell off the terminals again. And get back on there.

[00:29:15]Sorry. 5.95.

[00:29:17]And it's 307 microhenry. So it's got more a little bit it's got around about uh you know 300 microhenry's inductance 307 it's a little bit more inductive not going to do much um with more inductance it uh it's it did have a uh a higher self-ressonant frequency but if you have more inductance the frequency should go down right so it's counter intuitive um which in in that case means a core tech coil is really good. But the real test here is going to be this old mine lab. I I'm really intrigued even after many many years ago one of the mine lab guys say we we we specialize in detectors not coils. I always thought that was a good one. I won't say who said it. still might have shares in the company or something, but um it's pretty funny. Pretty funny. Okay, this is the old dunger thing. I I'll lift it up so we don't get any, you know, it's not sitting on metal or anything like that.

[00:30:30]We just have a look. Doesn't make any difference really. Anyway, get those prongs there and stick it in there and uh we'll have a look and see what we got.

[00:30:51]quite interesting.

[00:30:57]Okay.

[00:30:59]4.6.

[00:31:02]So, it's got a lower Q. And the interesting thing is I slipped off again.

[00:31:12]This is uh made for measuring capacitors. I should go in these other holes here, but you need leads and it'll it'll add a bit of inductance to it. So, I'm going in hard.

[00:31:25]I keep slipping off.

[00:31:30]Okay. 287.7 and a Q.

[00:31:41]Wait for it to settle a little bit.

[00:31:46]About 4.2.

[00:31:51]H.

[00:31:53]Interesting.

[00:31:55]Now, I'd say there's a lot of stuff I was going to say. It It would probably um make people make coils differently if I said what I was going to say. Uh does it really make any difference if I if I tell you what the problems are with these coils? Possibly.

[00:32:31][sighs] The thing is, if I if I just say if I ever ever wanted to make coils and I wanted to make better coils and I had a trick up my sleeve to make a better coil, which at the moment I know I can, you can prove that easy. But, um, what if I told all the coil manufacturers out there, what's wrong with these coils?

[00:32:53]and and I said, "Oh, and and put them on the path to experimenting to fix it."

[00:32:59]And uh or I could just say, "Well, there's something uh wrong with these coils." And if you do this and you do that and you don't do that and you, you know, do it in a different way, you'll make a better coil. Guess what? I just made myself a ton of competition. Right? So, I've learned not to say anything. Um, not to say anything like like that, but you know there is problems with the coil designs and uh I wonder what it is.

[00:33:36]No, I'm I'm being serious. There's there's actually there's issues with those coil designs. Um, all of them.

[00:33:45]You can tell because you know the parameters of the core. You can measure it. You can measure the uh um series DC resistance. You can measure the AC resistance. You can measure um basically a given amplitude with minimal loading.

[00:34:00]Uh there's a lot of parameters you can measure. And if you're not getting a um a high selfress resonant uh unloaded response from the signal generator by looking at on oscilloscope.

[00:34:15]Well, where's that energy going?

[00:34:19]I wonder um why is it so? Why is a round coil made out of litz wire got a lower Q um than a squashed up elliptical?

[00:34:35]Uh why has a coil with technically more inductance got a higher self-ressonant frequency with one that has less? There's only uh there's only another factor really that can control that and it's not the resistance.

[00:34:55]So we're talking ignore the resistance of the coils.

[00:34:59]We're talking an LC structure, right?

[00:35:03]So if one's got uh more L, right, and it's got a higher self-ress resonant frequency, it must have less C. Uh so anyway, that's that's that's um I'm giving the game away a little bit here by telling you what it is, but uh uh think about it. Uh it's um it's not rocket science.

[00:35:28]It's basic electrical theory and uh you can measure it and prove it. So yeah, um do that guys. Measure your coils.

[00:35:39]measure it. Just measure it. Um, put it a resistor in series. Uh, don't load it with uh the capacitance of the probe.

[00:35:48]Put it on 10 times. Adjust everything and sweep it and see where your peak is and uh it will tell you a story. But it's not if you just got one coil, it's not going to tell you anything. You know, it might come up and say, "Oh, it's 600 kHz." You go, "Oh, yeah. Well, you know, it's the same as a bucket of water." But um, you need two two buckets and different amounts of water in it, don't you? So you need a reference coil and you need to measure against your reference. Uh if it's better, it's better and if it's worse, it's worse. So yeah, that's just how it is. You don't know what's the best coil. Uh I made a coil, a really good coil once and uh I'm trying to recall that I had the self-ressonant frequency about 720 kHz.

[00:36:30]That's a long shot more than what these are. But that that's run-of-the-mill how they make it. If you want to see Oh, I'm not going to do it. I was going to show you um how how a double D looks.

[00:36:44]And uh I I could I have to go and change the connector wires to do that. But uh if you have a look at the Q on the uh receive coil, right?

[00:36:56]and the self-ressonant frequency, you know, you'll you'll roll around the ground laughing if you know what it means. It's an absolute slug of a thing.

[00:37:04]Very very very lossy. It's not very good. The uh double D coils, they're I'm talking about, you know, dime a dozen ones that are everywhere. They're not a good coil. Uh they're not made properly.

[00:37:16]They're I'm not going to say I'm not going to say there's a way to make it a beautiful double D coil. It's not the way they're made. Okay. Um there there's some good some tricks to it. We'll say that. But uh they're they're an interesting thing.

[00:37:35]Um you know, there's so much stuff I know and I know no one else knows it. I just know. Um because it's not used. It's not used in any of the new coils either.

[00:37:48]There's ways of doing things that's just not done and it should be done because it's it uh is less lossy and it raises the efficiency of the coil. Uh I'm talking double D's double D type coils or any any type of uh um separate null receive transmit offset type coil setup.

[00:38:08]No matter what it is there's ways and mean not going to say I nearly said it.

[00:38:14]I know he said it because I I it's just so obvious. Um I'll leave it there. I've said too much.

[00:38:26]But guys, you know, there's an old Keltech said, I think it was. Uh and uh it used to say, "Well, oils ain't oils."

[00:38:37]Well, coils ain't coils.

[00:38:41]I think it's quite funny. But yeah, that's that's um there you go. No smoking mirrors. Just do it as it is and you see it and that's it. So there you go. Um now the question is what would happen if we got a Ctech Elite Max mono coil that was round?

[00:39:08]Would it be even more efficient? It should be um should it have a higher self-ressonant frequency? Technically, yes.

[00:39:21]Should it have greater amplitude at the self-ressonant frequency? Yes, it should have. But like I say, I don't have every coil made by every manufacturer under the sun. So, I can't test them all. And uh they they wouldn't even lend me one to test. I tell you that I tell the truth about it.

[00:39:42]Um, but it it is as long as we got some, we can test them. And uh, like I say, there's nothing wrong with this. There's nothing wrong with it. And I I know why it reads the way it does. It's because it is an elliptical. It's not a perfect round coil. So, it is suffering field cancellation, but they all ellipticals will. It's it's just physics. it can cannot not suffer um its own field cancellation by interaction um by having it squashed in like that. Um it's not a proper balanced setup. Anyway, um I hope you learned something from that because I did especially testing the other thing. I don't know what's going on there. Well, I do. I just don't want to say what it is. Um but if if someone if someone rang me up and asks me very nicely, I tell them what uh what it is and um how to how to improve it. But that but uh I think in a lot of cases uh people won't do that because they know better. They know better. They all know better. They know better than me anyway, don't they? So um that's why I'm not in the business of making coils and they are Oh dear. Oh god. Sorry. I'm not I'm not blowing my own trumpet or anything, even though it sounds like I am and it sounds like I'm being a bit of a smarty pants, but uh uh when you've been doing this stuff for years and years and years and you just pick it up, look at it, you go wrong, let's put it down, right? It it it uh the mind boggles.

[00:41:17]Um may maybe I have to do do something one day. I say this is how you Well, I already have done that actually. How to make a coil. How to make a really good coil. I don't know if anyone ever noticed how I did it because no one's ever copied it. It's um probably about 300 videos back or something, but a long time ago I said how to make a really really good coil and uh all the ways means and there's some really important stuff there which I think everyone just glossed over and thought, "Oh, that's not important."

[00:41:50]Yes, it is. I wouldn't have done it if it wasn't important. It's um quite amazing. Anyway, guys, um you're all probably running around compromised coils and you don't know it. Uh well, if you get an elliptical, it's already compromised, but around one, look, really, I I can't say anything um um adverse on the Coiltech coils. They do work. Uh that Nugget Finder, I'm it it's probably not representive representative of uh their coils. There's something funny with that one.

[00:42:27]I'm making excuses now. Um, no, something funny going on. Okay, we'll just leave it there. But if you actually um have the same size coil and you have a given target and you actually put it on the ground and uh do some uh tests.

[00:42:43]Don't do tests like I do and everyone else does, you know, waving things in front of the coil. actually make up a test stand, something out of foam blocks. It's inert and uh you know have a firm bottom and just move the target under the coil and put the other coil on it and just have a look at uh you can listen to it with your ears. You're probably better off looking at peak amplitude on a storage oscilloscope or something of that nature. So it uh it it captures the peaks and you can log it and then yeah do the same thing. you move the target all over the place and uh then you see if you get greater peaks or not, it'll store it because trying to look at a peak and then say, "Oh, it was there or was it there?" It's very difficult. I mean, we do that out in the field with um test targets and that, you know, 10% error. So, what um you know, trying to keep your bloody arm straight, you know, like after you've been doing it for half an hour, it's very hard. Um, you know, you probably know too when you go swinging your coil, you probably end up dragging on the ground half the time, you know, halfway through the day. So, uh, yeah, I'm I'm I'm intrigued. I'm going to I'm going to look at that and fix it.

[00:43:58]Anyway, leave her there.