1 00:00:04,240 --> 00:00:12,600 Speaker 1: Get in touch with technology with tex stuff from Hey 2 00:00:12,640 --> 00:00:14,920 Speaker 1: there everyone, and welcome to tech stuff. This is Jonathan 3 00:00:14,960 --> 00:00:19,159 Speaker 1: Strickland with another classic episode. Don't worry, We're gonna have 4 00:00:19,239 --> 00:00:21,920 Speaker 1: new ones really soon, but this one is a pretty 5 00:00:21,960 --> 00:00:23,800 Speaker 1: cool one. It's one that I really enjoyed doing with 6 00:00:23,880 --> 00:00:27,840 Speaker 1: Chris Paillette several years ago. It's all about metal detectives, 7 00:00:27,840 --> 00:00:33,960 Speaker 1: how they were today we are going to talk about. 8 00:00:34,640 --> 00:00:37,120 Speaker 1: You know what, this was a topic that I don't 9 00:00:37,159 --> 00:00:40,080 Speaker 1: know that anyone has ever requested. Um. It came to 10 00:00:40,120 --> 00:00:44,040 Speaker 1: me actually as I was looking through stuff in my 11 00:00:44,040 --> 00:00:47,920 Speaker 1: basement and went metal detectors. We should talk about We've 12 00:00:47,920 --> 00:00:50,720 Speaker 1: never talked about metal detective Actually, we've sort of talked 13 00:00:50,720 --> 00:00:54,040 Speaker 1: about metal detectors because metal detectors use a lot of 14 00:00:54,080 --> 00:00:58,080 Speaker 1: the technology we talked about before, especially the relationship of 15 00:00:58,360 --> 00:01:02,480 Speaker 1: magnetism to atricity. Yeah. Um, but yeah, I mean it's 16 00:01:02,520 --> 00:01:06,120 Speaker 1: something that we run into very often, especially if we 17 00:01:06,160 --> 00:01:08,520 Speaker 1: travel and walk through the metal detectors at the airport 18 00:01:08,840 --> 00:01:12,080 Speaker 1: if we're not getting back scattered or you know, dropping 19 00:01:12,120 --> 00:01:14,800 Speaker 1: stuff that you can't find, losing your wedding ring and 20 00:01:14,959 --> 00:01:19,280 Speaker 1: the maltch outside. Yikes, that's good stuff. I've done that 21 00:01:20,280 --> 00:01:22,440 Speaker 1: I still have it, So there you go. I've never 22 00:01:22,480 --> 00:01:27,000 Speaker 1: lost my wedding ring. Alright, well it was only temporary. 23 00:01:27,640 --> 00:01:31,000 Speaker 1: So anyway, metal detectors talk about what they are. We're 24 00:01:31,040 --> 00:01:34,039 Speaker 1: mostly going to be talking about the kind that you 25 00:01:34,040 --> 00:01:37,400 Speaker 1: would you would carry with you, you know, the portable 26 00:01:37,400 --> 00:01:40,640 Speaker 1: metal detectors that you would use when looking for say, 27 00:01:40,680 --> 00:01:44,320 Speaker 1: loose change on the beach, or you know, searching for 28 00:01:44,400 --> 00:01:50,280 Speaker 1: that rare civil war uh bullet or a gun that 29 00:01:50,480 --> 00:01:52,560 Speaker 1: might be part of you know, in an area that 30 00:01:52,600 --> 00:01:55,120 Speaker 1: you knew the battle happened here, so there may very 31 00:01:55,200 --> 00:01:58,160 Speaker 1: well be stuff here. Yeah, we should definitely talk about 32 00:01:58,200 --> 00:02:00,920 Speaker 1: some of the applications of the technology GUM. And I 33 00:02:01,160 --> 00:02:02,960 Speaker 1: would like to point out that we have an excellent 34 00:02:03,040 --> 00:02:05,080 Speaker 1: article on how stuff Works dot com if you're interested 35 00:02:05,120 --> 00:02:09,760 Speaker 1: in learning more. Um it's called how Metal Detectors Work. Yeah. 36 00:02:09,760 --> 00:02:11,760 Speaker 1: It should be pretty easy for people to find, written 37 00:02:11,800 --> 00:02:15,440 Speaker 1: by Jeff Tyson, and it is a very good article 38 00:02:15,600 --> 00:02:20,080 Speaker 1: and very uh simple to follow, easy to understand. I 39 00:02:20,080 --> 00:02:22,519 Speaker 1: would say this is this is one of those really 40 00:02:22,639 --> 00:02:26,040 Speaker 1: great how stuff works articles. By the time you get 41 00:02:26,080 --> 00:02:28,400 Speaker 1: through it and you're like, oh, yeah, no, that totally 42 00:02:28,480 --> 00:02:31,359 Speaker 1: makes sense, especially if you have a little bit of 43 00:02:31,400 --> 00:02:37,560 Speaker 1: grounding in the way electromagnetism works and conductors and inducers. 44 00:02:38,600 --> 00:02:41,480 Speaker 1: So we'll we'll cover that. I mean, we've talked about 45 00:02:41,480 --> 00:02:44,120 Speaker 1: an in previous podcast, but we'll we'll do a quick 46 00:02:44,160 --> 00:02:47,880 Speaker 1: brush up so that we can explain it. So you wanna, 47 00:02:48,080 --> 00:02:50,639 Speaker 1: let's let's talk about the the Jeff does a great 48 00:02:50,720 --> 00:02:55,120 Speaker 1: job at breaking down what the typical portable metal detector, 49 00:02:55,200 --> 00:02:58,679 Speaker 1: the four main parts of one, what they would be. Yeah, 50 00:02:58,680 --> 00:03:01,400 Speaker 1: I mean, if you've ever seen people walking around with 51 00:03:01,880 --> 00:03:03,840 Speaker 1: a metal detector, you you sort of know what they 52 00:03:03,880 --> 00:03:07,000 Speaker 1: look like. They have a round dish part that's used 53 00:03:07,080 --> 00:03:11,839 Speaker 1: close to the ground. That's a that's called the coil. Then, yes, 54 00:03:11,919 --> 00:03:16,040 Speaker 1: and then you have the stabilizer um, which is the 55 00:03:16,080 --> 00:03:18,640 Speaker 1: part that you actually hold onto, that holds onto your 56 00:03:18,919 --> 00:03:21,400 Speaker 1: that that you see under your arm, because you know, frankly, 57 00:03:22,120 --> 00:03:24,960 Speaker 1: having used a metal detector, it's not the lightest thing, right. 58 00:03:25,520 --> 00:03:28,400 Speaker 1: This This helps, This helps distribute the weight somewhat so 59 00:03:28,480 --> 00:03:31,160 Speaker 1: that you're not you don't feel like you're carrying around 60 00:03:31,200 --> 00:03:34,920 Speaker 1: a you know, ten pound brick the whole time, because 61 00:03:34,960 --> 00:03:38,600 Speaker 1: without that then you would get very tired very quickly. Yeah, 62 00:03:38,680 --> 00:03:41,040 Speaker 1: And the the ten pound the aforementioned ten pound brick, 63 00:03:41,080 --> 00:03:43,600 Speaker 1: which probably isn't ten pounds, but it certainly can feel 64 00:03:43,600 --> 00:03:46,640 Speaker 1: that way after a while. That's the control box, uh, 65 00:03:46,640 --> 00:03:49,640 Speaker 1: and you've got all your your electronics in there. And 66 00:03:49,640 --> 00:03:55,960 Speaker 1: and then then yes, the long skinny part that's the shaft. Yes, 67 00:03:56,040 --> 00:03:58,800 Speaker 1: it connects the coil at the base to the part 68 00:03:58,880 --> 00:04:01,280 Speaker 1: that you're holding, and the of course the control box. 69 00:04:01,600 --> 00:04:04,240 Speaker 1: So those are your four basic parts of your basic 70 00:04:04,440 --> 00:04:07,840 Speaker 1: metal detector. Yes. And then you know you have your headphones, 71 00:04:08,040 --> 00:04:11,120 Speaker 1: because this is one of our episodes of stuff that 72 00:04:11,240 --> 00:04:14,280 Speaker 1: beeps and stuff what beat stuff? What beeps and it 73 00:04:14,360 --> 00:04:17,400 Speaker 1: it does in fact beep. Yeah, there's usually some sort 74 00:04:17,400 --> 00:04:22,920 Speaker 1: of audible alert that you have in fact detected metal. Yeah. Now, 75 00:04:23,120 --> 00:04:26,320 Speaker 1: more sophisticated uh, metal detectors will tell you a lot 76 00:04:26,360 --> 00:04:29,680 Speaker 1: more often with uh, well sometimes with with an audible tone, 77 00:04:29,720 --> 00:04:33,520 Speaker 1: but also with a visual uh, some kind of visual analysis. 78 00:04:33,880 --> 00:04:36,120 Speaker 1: We can get into that too in a minute. So 79 00:04:36,560 --> 00:04:40,880 Speaker 1: there are three main types of metal detectors, the ones 80 00:04:40,920 --> 00:04:46,440 Speaker 1: at work, the three three main approaches to to metal detection. 81 00:04:46,640 --> 00:04:50,440 Speaker 1: Let's say, uh, there's, um, there's the very low frequency, 82 00:04:50,520 --> 00:04:54,520 Speaker 1: which is probably the most the most popular or the 83 00:04:54,560 --> 00:04:56,840 Speaker 1: most common type of mel detector, at least for the 84 00:04:57,160 --> 00:05:01,040 Speaker 1: portable metal detectors. Um. Yeah, they When we get into this, 85 00:05:01,120 --> 00:05:03,400 Speaker 1: you'll you'll see that each of these different types has 86 00:05:03,440 --> 00:05:06,560 Speaker 1: its own strengths and weaknesses. And you might say, well, 87 00:05:06,640 --> 00:05:09,799 Speaker 1: the VLF detector sounds great, why would you use the others? 88 00:05:10,000 --> 00:05:12,960 Speaker 1: We'll get into that. Yeah. The other two are pulse 89 00:05:13,080 --> 00:05:18,560 Speaker 1: induction and beat frequency oscillation. Yeah. I knew a beat 90 00:05:18,640 --> 00:05:26,160 Speaker 1: frequency oscillator once. He was awesome. Yeah, Anyway, something else. 91 00:05:26,200 --> 00:05:31,280 Speaker 1: I guess that's the beat boxer frequency oscillator. That the uh, 92 00:05:31,440 --> 00:05:34,240 Speaker 1: the VLF metal detector is the type that I have, 93 00:05:35,160 --> 00:05:41,320 Speaker 1: UM and Uh. The the basic differences uh, and these 94 00:05:41,480 --> 00:05:45,479 Speaker 1: is you'll see those really in the coils, to be honest, 95 00:05:45,960 --> 00:05:51,640 Speaker 1: because the VLF has two different coils. One transmits UM 96 00:05:51,800 --> 00:05:54,480 Speaker 1: and and the other is basically an antenna to pick 97 00:05:54,600 --> 00:05:57,160 Speaker 1: up the signals, so they're shielded from one another so 98 00:05:57,240 --> 00:06:00,120 Speaker 1: it doesn't pick up because otherwise you turned it on, 99 00:06:00,160 --> 00:06:02,360 Speaker 1: you would just have the receiver saying, oh my gosh, 100 00:06:02,400 --> 00:06:07,200 Speaker 1: there's metal everywhere. Holy crap, you're rich even up in 101 00:06:07,240 --> 00:06:10,920 Speaker 1: the air. It's it's literally everywhere. Yeah, that would that 102 00:06:10,960 --> 00:06:13,359 Speaker 1: would not be very useful. And taking this back to 103 00:06:13,440 --> 00:06:16,920 Speaker 1: the store where it's a detector detector. This does not 104 00:06:17,000 --> 00:06:19,800 Speaker 1: do me any good. It's a detect it's a detected 105 00:06:19,839 --> 00:06:27,320 Speaker 1: at or where's perry. So the the the transmitter coil 106 00:06:27,839 --> 00:06:31,880 Speaker 1: um it's it. Think of a circle, all right, It's 107 00:06:31,920 --> 00:06:35,960 Speaker 1: a this circular part at the base of the metal detector. 108 00:06:36,480 --> 00:06:38,279 Speaker 1: And if you were to take it apart, which I 109 00:06:38,320 --> 00:06:40,920 Speaker 1: do not recommend you do, you would see that there 110 00:06:41,000 --> 00:06:44,279 Speaker 1: is a pointer warranty and it may not work anymore. 111 00:06:44,600 --> 00:06:47,279 Speaker 1: You will have a there's a coil of wire that 112 00:06:47,360 --> 00:06:50,560 Speaker 1: goes around the perimeter of this circle like it's it's 113 00:06:50,560 --> 00:06:53,240 Speaker 1: wrapped around. So the circle itself is let's say it's 114 00:06:53,240 --> 00:06:55,240 Speaker 1: like a quarter of an inch thick, and you've got 115 00:06:55,240 --> 00:06:57,520 Speaker 1: this coil of wire that's that's coiled around this quarter 116 00:06:57,520 --> 00:06:59,839 Speaker 1: of an inch all the way around the perimeter of 117 00:06:59,839 --> 00:07:03,599 Speaker 1: this circle. When you run electricity through this coil of wire, 118 00:07:04,279 --> 00:07:07,240 Speaker 1: what happens besides the fact that electrons are moving through 119 00:07:08,000 --> 00:07:13,400 Speaker 1: because of the nature of electricity and magnetism, well, when 120 00:07:13,440 --> 00:07:16,840 Speaker 1: you run electricity around a coil like that, it generates 121 00:07:16,920 --> 00:07:20,480 Speaker 1: a magnetic field. That's right, it does generate a magnetic field, 122 00:07:20,760 --> 00:07:24,080 Speaker 1: and it generates a magnetic field perpendicular to the direction 123 00:07:24,120 --> 00:07:28,000 Speaker 1: of the electricity. It's just the nature of electromagnetism. It's amazing, 124 00:07:28,280 --> 00:07:31,600 Speaker 1: it's awesome. That's what how electro magnets work and UH, 125 00:07:32,000 --> 00:07:36,480 Speaker 1: dynamo's work in UH and sort of using this in reverse. UM. 126 00:07:36,560 --> 00:07:40,120 Speaker 1: So you've got electricity flowing through these coils and that 127 00:07:40,200 --> 00:07:43,880 Speaker 1: generates the magnetic field. Well, it doesn't just the electricity. 128 00:07:43,880 --> 00:07:46,960 Speaker 1: Electricity doesn't just flow in one direction, no, it it 129 00:07:47,240 --> 00:07:50,680 Speaker 1: goes back and forth. It alternates very very very fast, 130 00:07:51,280 --> 00:07:53,440 Speaker 1: almost as fast as I waffle back and forth on 131 00:07:53,440 --> 00:07:55,840 Speaker 1: what I want to eat for lunch. And that means 132 00:07:55,920 --> 00:08:01,040 Speaker 1: that the magnetic field also alternates. The the direction of 133 00:08:01,080 --> 00:08:04,640 Speaker 1: the magnetic field changes. UH. And if you think of 134 00:08:04,680 --> 00:08:09,040 Speaker 1: it in terms of the disc, the coil disc being 135 00:08:09,240 --> 00:08:11,240 Speaker 1: towards the ground, you can think of it as the 136 00:08:11,280 --> 00:08:15,200 Speaker 1: magnetic field occasionally is pushing against or pulling the ground 137 00:08:16,000 --> 00:08:17,840 Speaker 1: in general. That just think of it that way. That's 138 00:08:17,840 --> 00:08:20,000 Speaker 1: the direction of the magnetic field, while the electricity is 139 00:08:20,000 --> 00:08:22,280 Speaker 1: going around and around in a circle, back and forth 140 00:08:22,360 --> 00:08:26,120 Speaker 1: in in the various directions, and that alternation is happening 141 00:08:27,480 --> 00:08:31,880 Speaker 1: hundreds of times per second. So you've got this magnetic field. 142 00:08:31,880 --> 00:08:35,640 Speaker 1: That's that's just oscillating essentially right there against the ground. 143 00:08:36,440 --> 00:08:39,640 Speaker 1: When it comes to contact with something that is metal, well, 144 00:08:39,679 --> 00:08:42,880 Speaker 1: the metal will start to that magnetic field will cause 145 00:08:43,080 --> 00:08:48,000 Speaker 1: a a weaker magnetic field to generate around the metal object. Yeah, 146 00:08:48,040 --> 00:08:52,360 Speaker 1: basically induces a magnetic field in a metal object in 147 00:08:52,360 --> 00:08:55,720 Speaker 1: the ground. So let's say, uh, um, you drop a 148 00:08:55,800 --> 00:09:00,600 Speaker 1: screw and when you're trying to build something outside and 149 00:09:00,600 --> 00:09:02,480 Speaker 1: you're trying to find it with your metal detector so 150 00:09:02,520 --> 00:09:04,080 Speaker 1: that you don't step on it with a bare foot 151 00:09:04,120 --> 00:09:06,280 Speaker 1: and you know, need a trip to the hospital and 152 00:09:06,320 --> 00:09:09,920 Speaker 1: a tetennis shot. Um. So as soon as you run 153 00:09:10,080 --> 00:09:12,280 Speaker 1: the coil of the field and you're not trying to 154 00:09:12,280 --> 00:09:14,200 Speaker 1: touch the ground with it, you really just need it 155 00:09:14,440 --> 00:09:17,960 Speaker 1: close to the ground. Um, it will find the screw. 156 00:09:18,240 --> 00:09:22,880 Speaker 1: The screw will basically start inducing a It will metal 157 00:09:22,880 --> 00:09:26,440 Speaker 1: detected detector will generate a field, and that will cause 158 00:09:26,520 --> 00:09:30,679 Speaker 1: the screw to generate its own a weaker magnetic Oh yeah, yeah, 159 00:09:30,720 --> 00:09:33,920 Speaker 1: considerably weaker, but it will the metal detector. Uh, the 160 00:09:33,960 --> 00:09:37,960 Speaker 1: antenna coil inside the transmitter coil will say, oh, look 161 00:09:38,040 --> 00:09:40,760 Speaker 1: there's something right there that is generating a magnetic field. 162 00:09:41,040 --> 00:09:45,160 Speaker 1: It's right here. And the way that the antenna works 163 00:09:45,640 --> 00:09:48,640 Speaker 1: is the way I was talking about with a dynamo. So, 164 00:09:48,679 --> 00:09:51,520 Speaker 1: if you have a coil of wire and you introduce 165 00:09:51,600 --> 00:09:55,040 Speaker 1: it into a fluctuating magnetic field, that will induce the 166 00:09:55,080 --> 00:09:58,920 Speaker 1: flow of electricity within the wire. Right, just as electricity 167 00:09:58,960 --> 00:10:01,600 Speaker 1: and the wire will create generated a magnetic field, a 168 00:10:01,600 --> 00:10:06,680 Speaker 1: magnetic field will induce electricity to run through wire fluctuating 169 00:10:06,720 --> 00:10:09,200 Speaker 1: magnetic field. It can't just be just a magnetic field. 170 00:10:09,800 --> 00:10:14,680 Speaker 1: So when the weak magnetic field from the metal object 171 00:10:14,760 --> 00:10:19,640 Speaker 1: hits that that the wire in the the the receiver 172 00:10:19,760 --> 00:10:25,560 Speaker 1: coil that generates the electricity, which then alerts the control 173 00:10:25,600 --> 00:10:28,760 Speaker 1: box that that's what When the control box gets an 174 00:10:28,760 --> 00:10:33,560 Speaker 1: electric signal from the receiver coil, that says beep, something 175 00:10:33,640 --> 00:10:38,480 Speaker 1: is here, stuff? What beeps? Yep? Stuff? What beeps? So yeah, 176 00:10:38,640 --> 00:10:44,240 Speaker 1: that's the basic uh way that a VLF metal detector works. 177 00:10:44,280 --> 00:10:48,960 Speaker 1: It shoots out this magnetic field. The polarization is alternating 178 00:10:49,400 --> 00:10:53,720 Speaker 1: the same as the flow of electricity around the the 179 00:10:53,720 --> 00:10:57,240 Speaker 1: the transmitter coil, and then the receiver coil picks up 180 00:10:57,320 --> 00:11:00,640 Speaker 1: any magnetic fields generated by metal objec that are under 181 00:11:00,679 --> 00:11:04,080 Speaker 1: the surface of the ground. It's pretty cool and generally 182 00:11:04,120 --> 00:11:07,960 Speaker 1: it will go more or less about a foot. Yeah, 183 00:11:08,160 --> 00:11:10,760 Speaker 1: you're not going to find you know, the Earth's core 184 00:11:12,559 --> 00:11:15,720 Speaker 1: with a metal detect and the depth of what the 185 00:11:15,800 --> 00:11:19,440 Speaker 1: depth of the The effectiveness of this metal detector is 186 00:11:19,480 --> 00:11:23,120 Speaker 1: also going to be dependent on other factors, like the 187 00:11:23,240 --> 00:11:26,600 Speaker 1: nature of the metal object itself, because some some metal 188 00:11:26,640 --> 00:11:29,680 Speaker 1: objects are going to generate a stronger magnetic field than others, 189 00:11:29,760 --> 00:11:34,760 Speaker 1: like iron. Uh. It will also depend on the composition 190 00:11:34,800 --> 00:11:37,360 Speaker 1: of the soil. Yes, So the soil has a lot 191 00:11:37,559 --> 00:11:41,120 Speaker 1: of elements in it that would create a magnetic field, 192 00:11:41,120 --> 00:11:43,520 Speaker 1: You're gonna get a lot of interference, yeah, or or 193 00:11:43,559 --> 00:11:49,680 Speaker 1: an environment where uh that that would conduct electricity more readily. 194 00:11:49,800 --> 00:11:51,720 Speaker 1: Like if you were trying to look for something and 195 00:11:51,760 --> 00:11:55,679 Speaker 1: say saltwater, you might have more difficulty than if you 196 00:11:55,720 --> 00:12:00,640 Speaker 1: were looking, you know, on on a different type of soil. Um. Now, 197 00:12:00,679 --> 00:12:04,720 Speaker 1: there is something to uh called phase shifting, Yes, And 198 00:12:04,760 --> 00:12:07,520 Speaker 1: that's how it's able to tell what sort of metal, 199 00:12:07,679 --> 00:12:10,920 Speaker 1: what sort of metal it is, UM. And it really 200 00:12:10,960 --> 00:12:14,000 Speaker 1: has to do with the the inductance and the resistance 201 00:12:14,240 --> 00:12:17,040 Speaker 1: of the object that you're looking for. Now, the inductance 202 00:12:17,120 --> 00:12:22,320 Speaker 1: is um the objects ability to conduct electricity UM and 203 00:12:22,360 --> 00:12:24,840 Speaker 1: if it's inductive, it will be able to to conduct 204 00:12:24,880 --> 00:12:29,679 Speaker 1: electricity easily, but it's slow to react to changes in 205 00:12:29,720 --> 00:12:33,400 Speaker 1: the electrical current. UM. If it's resistive, it doesn't conduct 206 00:12:33,480 --> 00:12:36,000 Speaker 1: electricity is easily, but it is quick to react to 207 00:12:36,040 --> 00:12:39,719 Speaker 1: those those changes. And a sophisticated metal detector will be 208 00:12:39,760 --> 00:12:43,280 Speaker 1: able to tell you, well, that's I think that's gold, 209 00:12:43,400 --> 00:12:46,199 Speaker 1: or I think that's high based upon that phase shift. 210 00:12:46,280 --> 00:12:48,679 Speaker 1: Because the phace scheft for a particular element is going 211 00:12:48,720 --> 00:12:52,360 Speaker 1: to remain constant, you know. That's that's why if it 212 00:12:52,400 --> 00:12:55,319 Speaker 1: didn't remain constant, then this wouldn't matter at all, because 213 00:12:55,320 --> 00:12:57,520 Speaker 1: it wouldn't you know, we wouldn't know. You know, It's 214 00:12:57,559 --> 00:12:59,679 Speaker 1: like we just know something is down there, we wouldn't 215 00:12:59,679 --> 00:13:02,360 Speaker 1: know have any way of guessing what it is. But 216 00:13:02,520 --> 00:13:07,320 Speaker 1: because it's an inherent property of this particular material and 217 00:13:07,360 --> 00:13:10,440 Speaker 1: it's really dependent upon the molecular composition of whatever that 218 00:13:10,520 --> 00:13:14,480 Speaker 1: material is, UM, then we can make start making guesses 219 00:13:14,480 --> 00:13:17,760 Speaker 1: based on that phase shift. UM. And it's yeah, the 220 00:13:17,760 --> 00:13:19,760 Speaker 1: face shift, you know, with it being that difference in 221 00:13:19,800 --> 00:13:24,520 Speaker 1: timing between the transmitters frequency UH and the frequency of 222 00:13:24,559 --> 00:13:29,080 Speaker 1: the magnetic wave that's generated by the object. UM. You 223 00:13:29,120 --> 00:13:33,679 Speaker 1: know it's these are sort of ranges, right like if 224 00:13:33,720 --> 00:13:36,320 Speaker 1: it if it's a certain range there, then the male 225 00:13:36,400 --> 00:13:39,520 Speaker 1: detector can give a best guess as to what that 226 00:13:39,600 --> 00:13:45,240 Speaker 1: material maybe. So there's never necessarily a guarantee that whatever 227 00:13:45,280 --> 00:13:48,920 Speaker 1: it is you've detected is specifically going to be you know, 228 00:13:49,000 --> 00:13:52,560 Speaker 1: aluminum versus goal or whatever. But it's a it's an indicator, 229 00:13:52,600 --> 00:13:56,040 Speaker 1: so that, uh, it gives you at least the idea 230 00:13:56,040 --> 00:13:59,000 Speaker 1: of you know, is that you measure risk versus reward, right, 231 00:13:59,760 --> 00:14:04,040 Speaker 1: the risk of exhausting yourself digging up useless junk versus 232 00:14:04,080 --> 00:14:08,520 Speaker 1: the reward of possibly finding something that is of true value. Yes, 233 00:14:08,760 --> 00:14:11,800 Speaker 1: so that's really the whole purpose of this anyways, just 234 00:14:11,880 --> 00:14:14,480 Speaker 1: you know, to kind of tune in on that beep 235 00:14:14,640 --> 00:14:17,000 Speaker 1: and make it more meaningful so that you know, you 236 00:14:17,040 --> 00:14:21,640 Speaker 1: don't waste your time digging up little poll tabs from 237 00:14:21,720 --> 00:14:27,360 Speaker 1: soda cans. Yeah. Now, yeah, if you have a higher inductance, 238 00:14:27,640 --> 00:14:30,440 Speaker 1: it's going to create a larger phase shift, and lower 239 00:14:30,440 --> 00:14:34,960 Speaker 1: inductance has a smaller phase shift. Now, metal detectors use 240 00:14:35,080 --> 00:14:40,680 Speaker 1: a phase demodulator to read this, and uh, what that 241 00:14:41,160 --> 00:14:45,720 Speaker 1: creates is discrimination. Yeah, yeah, I know it's terrible, but 242 00:14:46,280 --> 00:14:49,560 Speaker 1: oh no, not within metal detectors. It's okay, yeah, because 243 00:14:49,560 --> 00:14:52,800 Speaker 1: the thing is, a good metal detector will allow you 244 00:14:52,880 --> 00:14:57,520 Speaker 1: to filter out stuff that you don't want because the 245 00:14:57,560 --> 00:14:59,920 Speaker 1: metal detector, if you said it at a certain setting 246 00:15:00,080 --> 00:15:02,920 Speaker 1: and say, you know, I'm really looking for metals that 247 00:15:02,960 --> 00:15:06,600 Speaker 1: fall within this range, yeah, perhaps gold. I've actually seen 248 00:15:07,280 --> 00:15:10,920 Speaker 1: uh metal detector booths and they'll have like this giant 249 00:15:11,000 --> 00:15:14,920 Speaker 1: jar of class rings that people have lost, which is 250 00:15:14,920 --> 00:15:17,240 Speaker 1: sort of a you know, reminder that you know, hey, 251 00:15:17,280 --> 00:15:19,360 Speaker 1: you you can find stuff if you just take your 252 00:15:19,360 --> 00:15:22,840 Speaker 1: mel to Of course people look at you funny, but yeah, 253 00:15:23,040 --> 00:15:24,960 Speaker 1: that way. That way. Let's say that you're out there 254 00:15:25,000 --> 00:15:27,840 Speaker 1: looking for something specific, you can you know, some meld 255 00:15:27,880 --> 00:15:30,960 Speaker 1: detectors have settings where you can you can tell the 256 00:15:31,000 --> 00:15:34,760 Speaker 1: meld detector to ignore anything outside of a particular range 257 00:15:34,800 --> 00:15:37,200 Speaker 1: of frequencies. So, in other words, you're saying, you might 258 00:15:37,240 --> 00:15:41,560 Speaker 1: say I'm only interested in finding silver. Let's say, So 259 00:15:41,680 --> 00:15:43,560 Speaker 1: what I'll do is I'll set my meld detector so 260 00:15:43,640 --> 00:15:47,640 Speaker 1: that it'll it'll only uh activate, it will only alert 261 00:15:47,760 --> 00:15:53,640 Speaker 1: me if something that generates a magnetic frequency similar to 262 00:15:53,720 --> 00:15:57,120 Speaker 1: that of silver is encountered by the metal detector. So, 263 00:15:57,120 --> 00:15:59,000 Speaker 1: in other words, but you might you might pass over 264 00:15:59,040 --> 00:16:02,480 Speaker 1: a gold deposit and nothing happens. But as soon as 265 00:16:02,520 --> 00:16:05,640 Speaker 1: you go over that that silver half dollar. But and 266 00:16:05,680 --> 00:16:07,600 Speaker 1: then you dig it up and you're like, hey, look 267 00:16:07,600 --> 00:16:11,120 Speaker 1: I'm rich. I Meanwhile, the gold guy behind you was like, sucker. 268 00:16:12,520 --> 00:16:15,160 Speaker 1: Well that's that. That can be called notching. Basically, you 269 00:16:15,200 --> 00:16:18,480 Speaker 1: set it for a if you imagine a scale, uh 270 00:16:18,520 --> 00:16:21,320 Speaker 1: you know, one notch on that scale, or some of 271 00:16:21,320 --> 00:16:23,920 Speaker 1: the more sophisticated metal detectors will allow you to set 272 00:16:24,640 --> 00:16:26,560 Speaker 1: more than one notch, right, So that way you could 273 00:16:26,560 --> 00:16:29,240 Speaker 1: look for both silver and gold and you'd say, ha ha, 274 00:16:29,720 --> 00:16:34,480 Speaker 1: Mr smarty gold pants. Um. Now that's that's the VLF. 275 00:16:35,840 --> 00:16:39,240 Speaker 1: The post induction metal detectors a little bit different. Yeah, 276 00:16:39,240 --> 00:16:42,200 Speaker 1: it uses only a single coil, or it can use 277 00:16:42,240 --> 00:16:45,280 Speaker 1: multiple coils working at the same time. Yeah, but there 278 00:16:45,280 --> 00:16:47,880 Speaker 1: these are these are coils that haven't that don't have 279 00:16:47,920 --> 00:16:50,920 Speaker 1: that shielding. It's not like you have a transmitter coil 280 00:16:51,000 --> 00:16:54,600 Speaker 1: and then a receiver coil, and all of these coils 281 00:16:54,600 --> 00:17:00,640 Speaker 1: are generating very quick bursts of electric city, which of 282 00:17:00,680 --> 00:17:05,439 Speaker 1: course creates a very sharp magnetic wave. And uh so 283 00:17:05,480 --> 00:17:07,760 Speaker 1: it's just a really quick spike and then what will 284 00:17:07,800 --> 00:17:10,920 Speaker 1: happen is that magnetic wave if it encounters a metal object. Again, 285 00:17:11,160 --> 00:17:13,200 Speaker 1: that metal object will have to will generate its own 286 00:17:13,240 --> 00:17:17,960 Speaker 1: magnetic wave and the metal detector will pick up on that, 287 00:17:18,040 --> 00:17:20,320 Speaker 1: and it's all it's kind of like an echo. Right, 288 00:17:20,880 --> 00:17:23,520 Speaker 1: It's kind of like an echo, right, thank you. So 289 00:17:24,680 --> 00:17:27,240 Speaker 1: if you think about it that way, it's it's like 290 00:17:27,840 --> 00:17:30,960 Speaker 1: sending out a signal and waiting for something to bounce back. Yeah, 291 00:17:30,960 --> 00:17:33,240 Speaker 1: but it's very fast. I mean the average is about 292 00:17:33,280 --> 00:17:37,520 Speaker 1: a hundred pulses per second, which is yeah, fairly rapid, 293 00:17:37,560 --> 00:17:41,360 Speaker 1: pretty quick. And then you're looking for the reflected pulse, yes, 294 00:17:41,640 --> 00:17:44,960 Speaker 1: which is what the the object that is under the 295 00:17:45,000 --> 00:17:50,159 Speaker 1: ground or wherever. Uh, that's the the the pulse that 296 00:17:50,240 --> 00:17:53,040 Speaker 1: it generates in response to the one that came from 297 00:17:53,080 --> 00:17:56,440 Speaker 1: the metal detector. Yeah. Now it uses a these these 298 00:17:56,480 --> 00:17:59,280 Speaker 1: types of metal detectors use a sampling circuit basically trying 299 00:17:59,280 --> 00:18:03,120 Speaker 1: to deter whether it's actually metal that you're finding or 300 00:18:03,200 --> 00:18:05,840 Speaker 1: something else, some other type of magnetic field that is 301 00:18:05,880 --> 00:18:09,080 Speaker 1: interfering with this signal. And it's basically judging that based 302 00:18:09,119 --> 00:18:15,640 Speaker 1: on the amount of time it takes U two to reflect. Um. Yeah, 303 00:18:15,640 --> 00:18:17,480 Speaker 1: that's another thing that we should point out is that 304 00:18:17,520 --> 00:18:21,199 Speaker 1: metal detectors can encounter lots of different kinds of interference, 305 00:18:22,000 --> 00:18:24,400 Speaker 1: not just the composition of the soil. But let's say 306 00:18:24,400 --> 00:18:28,119 Speaker 1: that you happen to cross over where an electrical cable 307 00:18:28,160 --> 00:18:32,120 Speaker 1: has been buried. That could cause a problem. Your male 308 00:18:32,200 --> 00:18:34,920 Speaker 1: detector might think that, hey, look there's gold in them 309 00:18:34,920 --> 00:18:38,600 Speaker 1: the our hills, and truth, what you've hit is the 310 00:18:38,680 --> 00:18:41,240 Speaker 1: power line, which you don't want to dig that up. No, 311 00:18:41,600 --> 00:18:46,240 Speaker 1: it could result in everything from death, which is in 312 00:18:46,320 --> 00:18:50,479 Speaker 1: the metal detection BIS we call a bad thing, or 313 00:18:50,480 --> 00:18:54,600 Speaker 1: it could result in or and or it could result 314 00:18:55,080 --> 00:19:00,520 Speaker 1: in an entire region losing electricity. That's also a bad thing. 315 00:19:01,320 --> 00:19:03,600 Speaker 1: That's that's a very good point. I mean, these these 316 00:19:03,600 --> 00:19:06,159 Speaker 1: metal detectures are not only incredibly useful, they can be 317 00:19:06,160 --> 00:19:08,200 Speaker 1: a lot of fun. A lot of hobbyists love them. 318 00:19:09,280 --> 00:19:12,040 Speaker 1: But you do have to be very very careful. Um 319 00:19:12,160 --> 00:19:15,040 Speaker 1: and it's good to know your the territory to quote 320 00:19:15,040 --> 00:19:17,919 Speaker 1: a certain musical, but yeah, I mean you need to 321 00:19:17,920 --> 00:19:21,159 Speaker 1: know the territory. You gotta know where you're you're digging 322 00:19:21,640 --> 00:19:24,880 Speaker 1: because you you really could get hurt. Honestly, I got 323 00:19:24,960 --> 00:19:28,440 Speaker 1: Rock Island going through my head. Cash for the merchant 324 00:19:28,560 --> 00:19:33,920 Speaker 1: dies a. Sorry, all right. So we have an integrator 325 00:19:34,680 --> 00:19:39,040 Speaker 1: on these, on these pulse induction metal detectives, and that's 326 00:19:39,119 --> 00:19:42,159 Speaker 1: reading the signals from the sampling circuit and converting them 327 00:19:42,240 --> 00:19:45,320 Speaker 1: to d C. That's not current, yeah, not the district 328 00:19:45,359 --> 00:19:48,560 Speaker 1: of Columbia. Yeah, not not a comic book publisher either. 329 00:19:48,840 --> 00:19:51,359 Speaker 1: And that's feeding into it the audio circuit, and that 330 00:19:51,560 --> 00:19:55,520 Speaker 1: is what beats. Yeah, that's the stuff what beats. The 331 00:19:55,880 --> 00:19:59,119 Speaker 1: thing is, uh, these are very good at detecting metal, 332 00:19:59,200 --> 00:20:01,919 Speaker 1: but they're not very good at discriminating between different types 333 00:20:01,920 --> 00:20:05,639 Speaker 1: of metal. UM, So you're not going to get the 334 00:20:06,240 --> 00:20:09,040 Speaker 1: level of precision that you would get with the VLF 335 00:20:09,800 --> 00:20:13,320 Speaker 1: metal detector. But you know, they also you've got to 336 00:20:13,359 --> 00:20:16,000 Speaker 1: remember that these different types of detectors, while some of 337 00:20:16,040 --> 00:20:18,800 Speaker 1: them may work in conditions that others do not, there's 338 00:20:18,880 --> 00:20:23,520 Speaker 1: there's also a price range here as well. Oh yes, yes, now, yeah, 339 00:20:23,520 --> 00:20:29,040 Speaker 1: the beat frequency oscillator metal detectors can be uh fairly affordable. Um. 340 00:20:29,080 --> 00:20:31,679 Speaker 1: They also used two coils, but one is in the 341 00:20:31,720 --> 00:20:33,720 Speaker 1: search head and the other one is actually in the 342 00:20:33,760 --> 00:20:37,480 Speaker 1: control box. Um. They're connected to an oscillator that as 343 00:20:38,440 --> 00:20:43,080 Speaker 1: pulsing UM many many times per second, thousands of times 344 00:20:43,080 --> 00:20:46,800 Speaker 1: per second um. And and the and the frequency of 345 00:20:46,880 --> 00:20:49,200 Speaker 1: the one that's inside the control box and the one 346 00:20:49,240 --> 00:20:53,600 Speaker 1: that's inside the actual detector are slightly offset. They're not 347 00:20:53,800 --> 00:20:58,919 Speaker 1: in sync or Backstreet boys or oh you got the 348 00:20:58,920 --> 00:21:05,359 Speaker 1: other one I was gonna do so yeah, well, ironically 349 00:21:05,480 --> 00:21:09,000 Speaker 1: enough to our our current part of the conversation, they 350 00:21:09,240 --> 00:21:12,000 Speaker 1: create radio waves, um, and then the receiver in the 351 00:21:12,040 --> 00:21:16,439 Speaker 1: control box uh picks that up and plays tones to 352 00:21:16,600 --> 00:21:20,479 Speaker 1: let you know when you're you're coming into range of metal, right, 353 00:21:20,520 --> 00:21:25,639 Speaker 1: Because what's happening is that when the metal encounters this uh, 354 00:21:25,720 --> 00:21:30,080 Speaker 1: this this this electromagnetic field that is going to alter 355 00:21:30,640 --> 00:21:34,080 Speaker 1: that radio wave. And so what's really listening for our 356 00:21:34,160 --> 00:21:37,359 Speaker 1: changes in the sound that you're hearing. The change in 357 00:21:37,400 --> 00:21:41,280 Speaker 1: the sound indicates that you have encountered something that is 358 00:21:41,400 --> 00:21:44,560 Speaker 1: generating this magnetic field. Because of the one year generating, 359 00:21:44,840 --> 00:21:48,960 Speaker 1: they know what they're going through. UM. So yeah, I 360 00:21:48,960 --> 00:21:53,280 Speaker 1: mean detectors killed the radio star. But these these uh, 361 00:21:53,480 --> 00:21:56,880 Speaker 1: like I said, these are a lot cheaper to manufacture. 362 00:21:56,960 --> 00:22:00,439 Speaker 1: And therefore, if you are uh interested in getting your 363 00:22:00,440 --> 00:22:04,280 Speaker 1: feet wet uh and the metal detector the thing is 364 00:22:04,320 --> 00:22:06,600 Speaker 1: a hobby, you might consider this, but they're they're far 365 00:22:06,720 --> 00:22:09,919 Speaker 1: less accurate in terms of being able to give you 366 00:22:09,920 --> 00:22:14,119 Speaker 1: any kind of discrimination or any really any real control. 367 00:22:14,800 --> 00:22:17,880 Speaker 1: UM they actually use. These are the types of metal 368 00:22:17,880 --> 00:22:21,160 Speaker 1: detectors that you the handheld detectors that they use the airport. 369 00:22:22,040 --> 00:22:24,880 Speaker 1: Um you know, if you walk through the scanner and 370 00:22:24,880 --> 00:22:26,320 Speaker 1: and then yeah, that's the type they use in the 371 00:22:26,400 --> 00:22:29,680 Speaker 1: one because they don't really need to know whether it's 372 00:22:29,720 --> 00:22:32,320 Speaker 1: gold or iron. They just want to know what it 373 00:22:32,400 --> 00:22:35,080 Speaker 1: is that you've got now once once, once something beeps, 374 00:22:35,080 --> 00:22:37,000 Speaker 1: then they can say, all right, well let's see what 375 00:22:37,080 --> 00:22:41,120 Speaker 1: that is. They don't, you know, necessarily need to know immediately. Yeah, 376 00:22:41,160 --> 00:22:44,680 Speaker 1: And the metal detectors the frames at the airport, they 377 00:22:44,840 --> 00:22:47,680 Speaker 1: work on essentially the same principles we've talked about here. 378 00:22:48,119 --> 00:22:51,080 Speaker 1: They're generating electromagnetic fields, which of course has brought up 379 00:22:51,119 --> 00:22:56,080 Speaker 1: some concerns with people who may have UH devices like 380 00:22:56,160 --> 00:22:59,400 Speaker 1: medical devices that could react to electromagnetic fields. That's why 381 00:22:59,440 --> 00:23:02,920 Speaker 1: you occasion we hear about UH folks like that having 382 00:23:02,960 --> 00:23:06,560 Speaker 1: to go through like a pat down security as opposed 383 00:23:06,560 --> 00:23:09,200 Speaker 1: to a metal detector, just because of the concern that 384 00:23:09,280 --> 00:23:13,040 Speaker 1: it could interfere with a medical device. Right right now, 385 00:23:13,400 --> 00:23:16,359 Speaker 1: with with all of these UM, what you're gonna find 386 00:23:16,400 --> 00:23:19,440 Speaker 1: depends on the type of metal detector, the type of 387 00:23:19,760 --> 00:23:23,080 Speaker 1: metal that you're looking for, about how big it is, 388 00:23:23,119 --> 00:23:25,959 Speaker 1: the kind of makeup of the soil, um any kind 389 00:23:25,960 --> 00:23:30,240 Speaker 1: of interference from other objects, and the halo, which is basically, 390 00:23:30,760 --> 00:23:33,159 Speaker 1: you know, if you have a piece of metal in 391 00:23:33,200 --> 00:23:36,520 Speaker 1: the soil, it's going to read a little bit differently, 392 00:23:36,520 --> 00:23:38,919 Speaker 1: it's going to it's going to register is larger than 393 00:23:38,960 --> 00:23:42,320 Speaker 1: it actually is. Yeah, it's because those interesting things. Yeah, 394 00:23:42,400 --> 00:23:45,240 Speaker 1: they I could see your halo. I was I was waiting. 395 00:23:45,560 --> 00:23:48,560 Speaker 1: I was trying so hard not to go into that. 396 00:23:48,920 --> 00:23:52,920 Speaker 1: We've done so many songs references in this podcast, it's crazy, 397 00:23:53,040 --> 00:23:56,199 Speaker 1: and this might be our like our most intense that 398 00:23:56,440 --> 00:23:59,520 Speaker 1: the funny thing reference per minute other than the first one. 399 00:23:59,560 --> 00:24:03,920 Speaker 1: None of them have been metal. That's true, that's so. 400 00:24:04,200 --> 00:24:06,439 Speaker 1: But yeah, now that it is, really the halo effect 401 00:24:06,480 --> 00:24:08,800 Speaker 1: is really an interesting thing. It's just this the fact 402 00:24:08,800 --> 00:24:14,399 Speaker 1: that certain kinds of metal objects can actually increase the 403 00:24:14,480 --> 00:24:18,000 Speaker 1: conductivity of the soil that's around them, and the longer 404 00:24:18,040 --> 00:24:20,760 Speaker 1: that object, those particular objects have been in the ground, 405 00:24:21,160 --> 00:24:25,080 Speaker 1: the greater that conductivity change can be. So then yeah, 406 00:24:25,160 --> 00:24:27,400 Speaker 1: you might be like, hey, there's a there's a Sherman 407 00:24:27,480 --> 00:24:30,760 Speaker 1: tank down there is something. It just turns out that 408 00:24:30,760 --> 00:24:33,320 Speaker 1: there's another object that's been down there and has affected 409 00:24:33,320 --> 00:24:36,800 Speaker 1: the conductivity of the soil. That's pretty phenomenal. If you 410 00:24:36,840 --> 00:24:39,120 Speaker 1: have a Sherman tank buried in your backyard, please give 411 00:24:39,160 --> 00:24:43,280 Speaker 1: me a call. I'm I'm interested. Well not anymore, yeah, 412 00:24:43,320 --> 00:24:45,160 Speaker 1: I mean, well, you think about it. It makes sense 413 00:24:45,200 --> 00:24:47,919 Speaker 1: if you have let's say, let's say the aforementioned screw 414 00:24:48,440 --> 00:24:51,480 Speaker 1: and it's been there for a couple of years, let's 415 00:24:51,480 --> 00:24:55,360 Speaker 1: say iron and it's beginning to rust, it's beginning to disintegrate, 416 00:24:55,480 --> 00:24:59,280 Speaker 1: and you can change the conduct conductivity depending on the Again, 417 00:24:59,320 --> 00:25:02,480 Speaker 1: it also depend the soil. It's rain and you know, yeah, 418 00:25:02,480 --> 00:25:04,800 Speaker 1: it really depends upon the composition of the soil itself 419 00:25:04,840 --> 00:25:07,040 Speaker 1: as well. So, yeah, if there's a lot of iron 420 00:25:07,080 --> 00:25:10,439 Speaker 1: content in the soil, that's gonna cause some issues when 421 00:25:10,480 --> 00:25:12,439 Speaker 1: you're when you're doing metal detection, you know, you're just 422 00:25:12,920 --> 00:25:14,679 Speaker 1: you're gonna get a lot of interference and you just 423 00:25:14,680 --> 00:25:17,080 Speaker 1: have to factor that in. Doesn't mean that the metal 424 00:25:17,119 --> 00:25:18,840 Speaker 1: detector is going to be useless. It just means that 425 00:25:18,880 --> 00:25:22,800 Speaker 1: you have to kind of adjust your expectations and listen 426 00:25:22,920 --> 00:25:27,280 Speaker 1: for bigger changes in UH in the soil content and 427 00:25:27,359 --> 00:25:31,080 Speaker 1: not and kind of kind of ignore the noise, separate 428 00:25:31,119 --> 00:25:33,520 Speaker 1: the signal from the noise. Yeah, I would argue that 429 00:25:33,560 --> 00:25:37,159 Speaker 1: it probably takes some personal discrimination too. You really need 430 00:25:37,200 --> 00:25:39,159 Speaker 1: to get out there in practice if you're going to 431 00:25:39,160 --> 00:25:43,160 Speaker 1: start using doing metal detecting as a hobby, um, and 432 00:25:43,280 --> 00:25:45,359 Speaker 1: maybe even trying it with things that you what that 433 00:25:45,480 --> 00:25:49,280 Speaker 1: you know what they are. You know, some coins, a ring, 434 00:25:49,960 --> 00:25:53,280 Speaker 1: a screw driver, you know, something that hammer, you know, 435 00:25:53,359 --> 00:25:56,479 Speaker 1: German tanks, the stuff that you do just you know, 436 00:25:56,560 --> 00:25:59,280 Speaker 1: tend to run across in your general area. Well, you know, 437 00:25:59,359 --> 00:26:01,080 Speaker 1: you never know what going to find when you're out 438 00:26:01,080 --> 00:26:03,879 Speaker 1: in the field somewhere, and if you can identify what 439 00:26:03,960 --> 00:26:06,720 Speaker 1: they are, you can get a sense of what different 440 00:26:06,720 --> 00:26:09,440 Speaker 1: metals sound like. How get a feel for how your 441 00:26:09,440 --> 00:26:12,280 Speaker 1: metal detector works, Yeah, how sensitive it is and how 442 00:26:12,320 --> 00:26:15,560 Speaker 1: sensitive it is. Um. Yeah, it can be a lot 443 00:26:15,600 --> 00:26:17,760 Speaker 1: of fun to UH as you were talking about before, 444 00:26:17,920 --> 00:26:22,120 Speaker 1: like going to UH battlefields. Of course, I imagine probably 445 00:26:22,160 --> 00:26:25,400 Speaker 1: all the major battlefields have been picked pretty clean at 446 00:26:25,400 --> 00:26:28,720 Speaker 1: this point, you would think, But it's it's amazing once 447 00:26:28,760 --> 00:26:31,639 Speaker 1: you can stumble across It's again, it's one of those 448 00:26:31,640 --> 00:26:35,000 Speaker 1: things where it may be it may require a phenomenal 449 00:26:35,040 --> 00:26:39,000 Speaker 1: amount of luck. Sure experience, there's no such thing as luck, 450 00:26:39,840 --> 00:26:43,160 Speaker 1: but it may require a phenomenal a series of coincidences 451 00:26:43,160 --> 00:26:45,320 Speaker 1: in order for you to stumble across the right section 452 00:26:45,359 --> 00:26:49,000 Speaker 1: to find something significant. But really you never know. You 453 00:26:49,080 --> 00:26:52,680 Speaker 1: just it's it's amazing to me. How something that you 454 00:26:52,720 --> 00:26:55,200 Speaker 1: would think, oh, well, this has got so much traffic, 455 00:26:55,240 --> 00:26:57,879 Speaker 1: there's no way there's anything of significance can be found there. 456 00:26:57,880 --> 00:27:00,639 Speaker 1: And yet like five years later you'll find that the 457 00:27:00,720 --> 00:27:04,480 Speaker 1: find of the injury. How did that happen? Yeah, and 458 00:27:04,800 --> 00:27:09,320 Speaker 1: you don't know what's around in places that you know 459 00:27:09,480 --> 00:27:12,479 Speaker 1: might be a value. I mean again, people find I'm 460 00:27:12,520 --> 00:27:15,480 Speaker 1: still searching for black Beard's treasure, all kinds of stuff 461 00:27:15,560 --> 00:27:19,040 Speaker 1: out any time I go to the Carolina's out in 462 00:27:19,119 --> 00:27:22,480 Speaker 1: normal places. Maybe you should actually go to the everyday 463 00:27:22,480 --> 00:27:27,040 Speaker 1: beach instead of in land. That's probably part of the problem. Yeah, 464 00:27:27,240 --> 00:27:29,080 Speaker 1: you know, Charleston is so nice. I just like to 465 00:27:29,400 --> 00:27:33,479 Speaker 1: spend some time there. And yeah, people even use them 466 00:27:33,520 --> 00:27:37,400 Speaker 1: for prospecting, you know, and uh and for coin shooting. Now, 467 00:27:37,440 --> 00:27:40,000 Speaker 1: if you do want to use your mail detective for prospecting, 468 00:27:40,040 --> 00:27:43,000 Speaker 1: there are some things you need to remember first you 469 00:27:43,080 --> 00:27:46,760 Speaker 1: have to grow a beer of at least a foot 470 00:27:46,800 --> 00:27:49,240 Speaker 1: in length. That needs to be gray and grizzly. He's 471 00:27:49,240 --> 00:27:51,600 Speaker 1: gone punchy, ladies and gentlemen. Second, you need to be 472 00:27:51,640 --> 00:27:54,320 Speaker 1: able to say things like consarnate with a straight face. 473 00:27:54,520 --> 00:27:56,960 Speaker 1: And then third, the most important thing about being a 474 00:27:56,960 --> 00:27:59,240 Speaker 1: prospector is you have to develop your crazy prospect or 475 00:27:59,320 --> 00:28:04,080 Speaker 1: dance when you start gold. Very important. Yeah. Coin shooting 476 00:28:04,440 --> 00:28:08,760 Speaker 1: is the practice of looking for coins after an outdoor 477 00:28:08,760 --> 00:28:12,600 Speaker 1: event like a wedding or or like woodstock you go 478 00:28:12,640 --> 00:28:14,720 Speaker 1: to you go to some big outdoor conference and you 479 00:28:15,080 --> 00:28:18,560 Speaker 1: take a male detector and you start looking for for change. 480 00:28:18,920 --> 00:28:20,720 Speaker 1: The thing is that if you live in an area 481 00:28:20,760 --> 00:28:23,000 Speaker 1: where this sort of stuff goes on in a regular basis, 482 00:28:23,200 --> 00:28:27,080 Speaker 1: you could presumably pay off that mail detector after you know, 483 00:28:27,640 --> 00:28:32,520 Speaker 1: a few visits to these these areas, once the concert 484 00:28:32,640 --> 00:28:36,280 Speaker 1: is over or a game or whatever. Um you know. 485 00:28:36,400 --> 00:28:40,120 Speaker 1: And and because we're usually talking about change, you know 486 00:28:40,320 --> 00:28:44,160 Speaker 1: some some nickels or dimes or quarters or whatever whatever 487 00:28:44,240 --> 00:28:46,680 Speaker 1: money you use. You know, it's not all just United 488 00:28:46,720 --> 00:28:51,160 Speaker 1: States folks. Well, if you find euros, you're rich, because 489 00:28:51,200 --> 00:28:54,040 Speaker 1: I think a euro is equivalent to like seventeen dollars 490 00:28:54,080 --> 00:28:58,520 Speaker 1: at this point. Um, that's a gross exaggeration, but the 491 00:28:58,560 --> 00:29:02,240 Speaker 1: point being that, you know, yeah, you could conceivably pay 492 00:29:02,280 --> 00:29:08,920 Speaker 1: off your mail detective's cost after a few visits, you know. Um, 493 00:29:08,960 --> 00:29:11,719 Speaker 1: But although a lot of people just enjoy this as 494 00:29:11,760 --> 00:29:14,480 Speaker 1: a hobby, like it's just it's a way to get outside. 495 00:29:15,040 --> 00:29:18,320 Speaker 1: You're enjoying your drawing time outdoors and you're finding stuff 496 00:29:18,360 --> 00:29:22,920 Speaker 1: which just brings you a level of of of satisfaction 497 00:29:23,280 --> 00:29:25,920 Speaker 1: right A means that whole treasure hunting aspect, you know, 498 00:29:25,960 --> 00:29:28,200 Speaker 1: when I when we discover something, there's an element of 499 00:29:28,240 --> 00:29:31,240 Speaker 1: satisfaction there that you can't put a monetary value on. 500 00:29:31,600 --> 00:29:34,880 Speaker 1: Who Yeah, yeah you're just like, hey look I found 501 00:29:34,880 --> 00:29:38,880 Speaker 1: some money, woo, and yeah, there's there's an enjoyment level 502 00:29:38,920 --> 00:29:41,680 Speaker 1: there that goes beyond oh and it's worth you know, 503 00:29:41,760 --> 00:29:45,880 Speaker 1: seventy five cents um. Although the se cents it's always 504 00:29:45,920 --> 00:29:48,400 Speaker 1: nice to have seventy five cents more than you had, 505 00:29:48,400 --> 00:29:51,120 Speaker 1: but when you showed up at the field, So yeah, 506 00:29:51,160 --> 00:29:55,760 Speaker 1: I keep wondering, actually, why the value of the giant 507 00:29:55,800 --> 00:30:00,360 Speaker 1: jar of class rings. You'd figure they'd cash that in, Yeah, 508 00:30:00,440 --> 00:30:02,560 Speaker 1: I mean for more than just selling metal detectors. Maybe 509 00:30:02,560 --> 00:30:05,360 Speaker 1: that's more lucrative than selling off some of those classroom 510 00:30:05,600 --> 00:30:07,880 Speaker 1: prying out all the little jewels and melting that stuff 511 00:30:07,920 --> 00:30:10,960 Speaker 1: down and then just hey, you now can yourself bar 512 00:30:11,040 --> 00:30:18,800 Speaker 1: a gold? It's worth its waiting gold. I hope you 513 00:30:18,920 --> 00:30:21,640 Speaker 1: enjoyed that look back at tech stuff and remember, if 514 00:30:21,680 --> 00:30:23,240 Speaker 1: you want to get in touch with us, you can 515 00:30:23,320 --> 00:30:26,160 Speaker 1: send me an email. The address is tech stuff at 516 00:30:26,280 --> 00:30:29,160 Speaker 1: how stuff works dot com, or drop me a line 517 00:30:29,160 --> 00:30:32,520 Speaker 1: on Facebook, Twitter or Tumbler. The handle of all three 518 00:30:32,600 --> 00:30:35,240 Speaker 1: is tech stuff H s W. And I'll talk to 519 00:30:35,280 --> 00:30:41,560 Speaker 1: you again really soon. For more on this and thousands 520 00:30:41,560 --> 00:30:49,360 Speaker 1: of other topics, is it how stuff works dot com