1 00:00:00,130 --> 00:00:04,920 If you’re watching something like, well like this, on a modern display, you probably 2 00:00:04,920 --> 00:00:09,510 don’t think too much about what your device is doing to make this happen. It’s not really 3 00:00:09,510 --> 00:00:14,130 that extraordinary in this modern world filled with computers and microprocessors. In fact, 4 00:00:14,130 --> 00:00:18,710 I’m willing to bet you have a rough idea of how this works. But I’ll explain anyway. 5 00:00:18,710 --> 00:00:22,410 If you get up close to a TV or monitor, you find there’s a grid, made of millions of 6 00:00:22,410 --> 00:00:26,849 little squares called pixels. From far enough away, these pixels blend into each other, 7 00:00:26,849 --> 00:00:31,589 and our eyes and brains build a coherent picture. To actually create the image on the screen, 8 00:00:31,589 --> 00:00:35,330 each pixel can have some instructions sent to it to tell it how much light it should 9 00:00:35,330 --> 00:00:39,430 emit. A series of controller circuits work with millions of transistors to methodically 10 00:00:39,430 --> 00:00:44,470 give every one of these squares a specific brightness value 60 or 120 times a second, 11 00:00:44,470 --> 00:00:48,680 sometimes more often than that. The instructions are further divided into three separate values 12 00:00:48,680 --> 00:00:52,800 for red, green, and blue which when combined together can create practically any color 13 00:00:52,800 --> 00:00:54,030 you can think of. 14 00:00:54,030 --> 00:00:57,990 But have you ever wondered how old-school TV worked? We’ve been sending video signals 15 00:00:57,990 --> 00:01:03,530 over the air for a very long time, in fact analog television predates World War II. There 16 00:01:03,530 --> 00:01:07,859 weren’t computer or logic circuits decoding number values then, in fact there weren’t 17 00:01:07,859 --> 00:01:14,630 even pixels. Yet, this somehow worked. How? What magic is going on to take the signal 18 00:01:14,630 --> 00:01:19,079 coming over this wire and turn it into a black and white image of me, all without a single 19 00:01:19,079 --> 00:01:20,380 digital circuit? 20 00:01:20,380 --> 00:01:25,350 To find out, let’s make things really simple. Instead of looking at millions of pixels, 21 00:01:25,350 --> 00:01:30,890 let’s look at just one. A single pixel is really just a point of light. Without using 22 00:01:30,890 --> 00:01:35,420 any digital circuitry, how can we tell the light what to do? Easy, by controlling how 23 00:01:35,420 --> 00:01:36,630 much power it gets. 24 00:01:36,630 --> 00:01:41,780 Here’s an LED hooked up to a power supply. By simply varying how much voltage it gets, 25 00:01:41,780 --> 00:01:46,569 you can change how much light it emits. Using radio technology, it’s really easy to build 26 00:01:46,569 --> 00:01:50,240 a circuit that can control the brightness of this LED or another light source based 27 00:01:50,240 --> 00:01:55,850 on the strength of a signal transmitted over the air. Of course, this is clearly not television, 28 00:01:55,850 --> 00:01:58,020 but it’s at the core of what makes it work. 29 00:01:58,020 --> 00:02:03,079 See, we really suck at seeing things that happen quickly. Our eyes and brains are just 30 00:02:03,079 --> 00:02:07,779 no good at processing fast visual information. Thus, it’s really easy to trick our eyes 31 00:02:07,779 --> 00:02:11,950 into seeing something that’s not really there. If you take a light source and move 32 00:02:11,950 --> 00:02:16,150 it very quickly, you no longer see a single light source, instead you see a continuous 33 00:02:16,150 --> 00:02:20,800 line that follow the path of the light. Our brains can’t process the light’s fast 34 00:02:20,800 --> 00:02:25,410 motion, and it just blurs together into a solid line. This phenomenon is called persistence 35 00:02:25,410 --> 00:02:29,990 of vision. Now, if you manipulate the voltage of the light while you move it, you can make 36 00:02:29,990 --> 00:02:31,430 patterns in the line. 37 00:02:31,430 --> 00:02:36,870 You can find a lot of toys that exploit persistence of vision. This old 20Q game works using this 38 00:02:36,870 --> 00:02:41,600 principle. A small circuit board with a few LEDs on it spins in a circle really fast, 39 00:02:41,600 --> 00:02:45,710 too fast for your eyes to keep track of. If the LEDs were lit up all the time, it would 40 00:02:45,710 --> 00:02:50,660 just appear to be a continuous circle. But the game uses sensors to track where the LEDs 41 00:02:50,660 --> 00:02:55,610 are, and turns each of them on and off at very specific times. By manipulating the brightness 42 00:02:55,610 --> 00:03:00,080 of the LEDs and timing it with their motion, it can draw simple text and graphics using 43 00:03:00,080 --> 00:03:01,810 just eight points of light. 44 00:03:01,810 --> 00:03:06,680 But a CRT television like this has only one point of light to work with. After all, this 45 00:03:06,680 --> 00:03:11,830 is 1920’s technology, and multitasking wasn’t really a thing yet. So first, what actually 46 00:03:11,830 --> 00:03:17,480 makes the light? Well, CRT stands for cathode ray tube. The name comes from cathode rays, 47 00:03:17,480 --> 00:03:22,690 which were discovered by Johann Hittorf in 1869. William Crookes had created these goofy 48 00:03:22,690 --> 00:03:27,120 tube things that were really important to early scientific discovery. He was able to 49 00:03:27,120 --> 00:03:31,650 evacuate nearly all the air from these tubes, which allowed electrons to move freely within 50 00:03:31,650 --> 00:03:35,600 them, though no one yet knew what electrons were. When electric current was sent through 51 00:03:35,600 --> 00:03:40,120 these tubes, something caused them to glow. Johann Hittorf was the first person to piece 52 00:03:40,120 --> 00:03:44,320 together that whatever was causing this phenomenon travelled in straight lines from the cathode, 53 00:03:44,320 --> 00:03:48,210 or negative electrode, observing how a stencil between the cathode and the surface of the 54 00:03:48,210 --> 00:03:54,460 tube cast a shadow. Eugen Goldstein gave them the name Cathode Rays, just like rays of sunlight. 55 00:03:54,460 --> 00:03:58,540 J J Thompson would later use these tubes to work out what these cathode rays were actually 56 00:03:58,540 --> 00:04:03,220 made of, and in doing so he happened to discover the electron. So good on him. 57 00:04:03,220 --> 00:04:08,220 Before we continue, SAFETY WARNING: Exploring the innards of a CRT television can be quite 58 00:04:08,220 --> 00:04:12,780 dangerous. A set as small as this can generate over a thousand volts through the flyback 59 00:04:12,780 --> 00:04:18,260 transformer, and the CRT’s glass can store a lethal charge. I know what is and what’s 60 00:04:18,260 --> 00:04:22,180 not OK to touch, and since you likely don’t, don’t try this at home. 61 00:04:22,180 --> 00:04:26,100 If you’ve ever messed around with antique radios you’ll have seen vacuum tubes, which 62 00:04:26,100 --> 00:04:30,880 are the precursors to transistors. These electronic components have the air evacuated from them 63 00:04:30,880 --> 00:04:35,330 so electrons can move freely, just like the crookes tubes. Using a heater filament to 64 00:04:35,330 --> 00:04:39,240 induce thermionic emission from a cathode, they can manipulate electric current in a 65 00:04:39,240 --> 00:04:44,300 bunch of ways. A television CRT is really a specialized vacuum tube that has had its 66 00:04:44,300 --> 00:04:49,750 top blown way up and out to form a screen. It’s then mounted sideways in a cabinet, 67 00:04:49,750 --> 00:04:53,420 and your eyes stare at the front of it. That’s what brought about the phrase, watching the 68 00:04:53,420 --> 00:04:56,900 tube. And it also explains the name of this site. 69 00:04:56,900 --> 00:05:00,380 Because it has no air inside, it has to be pretty strong to counteract the force of the 70 00:05:00,380 --> 00:05:05,790 atmosphere always trying to crush it. That’s why larger tube TV’s are so heavy--the glass 71 00:05:05,790 --> 00:05:11,190 needs to be quite thick on larger sets. Most of the tube is empty space with the meat and 72 00:05:11,190 --> 00:05:16,571 potatoes being at the very back. Here you’ll find the awesomely named electron gun. This 73 00:05:16,571 --> 00:05:20,300 component generates a stream of electrons and they are shot straight out to the front 74 00:05:20,300 --> 00:05:25,070 of the tube. The flyback transformer generates an extremely high voltage in the anode to 75 00:05:25,070 --> 00:05:29,320 attract the electrons to the front of the screen. Coating the inside surface of the 76 00:05:29,320 --> 00:05:34,230 tube is a special powder known as a phosphor. When the electrons sent from the gun hit the 77 00:05:34,230 --> 00:05:38,990 phosphor, it gets all excited and emits light, via fluorescence, but only in the spot the 78 00:05:38,990 --> 00:05:40,240 electrons are hitting it. 79 00:05:40,240 --> 00:05:45,200 Here’s a working CRT with one of the critical components to television removed because we 80 00:05:45,200 --> 00:05:48,940 haven’t gotten that far. Don’t worry, we’ll get there. So, the CRT is doing a 81 00:05:48,940 --> 00:05:52,310 bang-up job producing a stream of electrons and they’re going straight to the front 82 00:05:52,310 --> 00:06:00,310 of the screen, and colliding with it to make it glow. And, this is the result. So fascinating. 83 00:06:00,310 --> 00:06:04,310 But hang on, there’s more to it. The vast majority of the signal coming into this television 84 00:06:04,310 --> 00:06:09,380 is simply telling it how bright to make this point of light. Therefore, a signal that alternates 85 00:06:09,380 --> 00:06:15,730 between bright and dark will make this happen. Amazing. That doesn’t do that much good. 86 00:06:15,730 --> 00:06:19,389 Ah, but you see, the point of light can be moved. 87 00:06:19,389 --> 00:06:23,260 One of the things Crookes and others noticed when mucking about with his tubes was that 88 00:06:23,260 --> 00:06:28,570 a magnetic field can bend an electron beam. In other words, you can use a magnet to alter 89 00:06:28,570 --> 00:06:33,340 the path the beam makes through the tube. Watch. Here’s an ordinary strong magnet 90 00:06:33,340 --> 00:06:38,090 used for a nametag. When I move it around the neck of the tube, the point of light moves 91 00:06:38,090 --> 00:06:44,060 around the screen, also. Mind bending, more like beam bending, amiright? 92 00:06:44,060 --> 00:06:49,570 So then, here comes the other bit. This little bundle of wires is called the deflection yoke. 93 00:06:49,570 --> 00:06:54,241 This is responsible for moving the beam really really quickly, and fooling your eyes. The 94 00:06:54,241 --> 00:06:58,320 yoke is made of two electromagnets that surround the neck of the tube, and they work together 95 00:06:58,320 --> 00:07:03,080 to move the electron beam around in a set pattern. It does this by creating a fairly 96 00:07:03,080 --> 00:07:08,169 strong magnetic field which will deflect the beam’s path. First, I’ll turn on the horizontal 97 00:07:08,169 --> 00:07:14,949 deflector. Now, rather than a point of light, we see a line. This line is being drawn on 98 00:07:14,949 --> 00:07:20,250 the screen thousands of times a second, way too fast for your eyes to notice. Just like 99 00:07:20,250 --> 00:07:25,360 the POV effect from the toy, if we carefully control how bright this line is as it moves 100 00:07:25,360 --> 00:07:35,280 left and right we can create patterns in the line like this. 101 00:07:35,280 --> 00:07:39,740 But the yoke contains another magnet that can move the beam up and down. Let me switch 102 00:07:39,740 --> 00:07:45,759 to that one. We now have a vertical line being drawn on the screen, and we can control its 103 00:07:45,759 --> 00:07:50,190 intensity just like the horizontal line to draw patterns. This vertical movement happens 104 00:07:50,190 --> 00:07:54,870 much more slowly than the horizontal movement, with the line only being drawn 60 times in 105 00:07:54,870 --> 00:08:00,139 a second. Now, since we can point the beam from left to right, as well as up and down, 106 00:08:00,139 --> 00:08:04,650 we can point it anywhere we want on the screen. Let’s turn on both electromagnets at the 107 00:08:04,650 --> 00:08:13,630 same time. We now have an image on the whole screen. Pretty neat, huh? By carefully controlling 108 00:08:13,630 --> 00:08:18,009 the intensity of the beam over time, we can create a complete image. 109 00:08:18,009 --> 00:08:22,140 If you look really closely at a black and white television, you won’t find pixels. 110 00:08:22,140 --> 00:08:27,150 Rather, you’ll find lines. See, the image is made of lines, in fact there are roughly 111 00:08:27,150 --> 00:08:33,710 525 lines that make up the NTSC signal, and about 480 are visible on the screen. The deflection 112 00:08:33,710 --> 00:08:38,440 yoke is making a pattern on the screen called a raster, and in NTSC countries, it’s drawn 113 00:08:38,440 --> 00:08:42,390 on the screen 60 times a second. There’s a bit of a trick, though, because the screen 114 00:08:42,390 --> 00:08:47,899 is only COMPLETELY redrawn 30 times a second. See, as the raster is drawn, only every other 115 00:08:47,899 --> 00:08:52,460 line is filled in. This is called a field, and it’s the principle behind interlaced 116 00:08:52,460 --> 00:08:58,060 video. That’s the i in 1080i. Because not-a-lot of bandwidth is available, the whole screen 117 00:08:58,060 --> 00:09:02,050 can only reasonably be filled in 30 times a second, but this would be noticeable as 118 00:09:02,050 --> 00:09:06,360 flicker and could give many people headaches. By skipping every other line and then repeating 119 00:09:06,360 --> 00:09:10,870 the scan to fill in the rest, the screen is drawn from top to bottom 60 times a second, 120 00:09:10,870 --> 00:09:15,110 which was too fast for most people to perceive flickering. Also, it allowed for smoother 121 00:09:15,110 --> 00:09:19,450 motion, with the caveat that fast-moving objects would have less detail as only every-other 122 00:09:19,450 --> 00:09:23,590 line is filled in with each field (however that never proved to be a huge concern as 123 00:09:23,590 --> 00:09:26,390 it’s hard to see detail in fast moving objects, anyway.) 124 00:09:26,390 --> 00:09:30,580 Side-note: It’s no coincidence that the 60 hz refresh rate matches the frequency of 125 00:09:30,580 --> 00:09:35,680 the AC electricity sent into homes, as the 60 hz sine wave coming from the socket powering 126 00:09:35,680 --> 00:09:40,940 the TV made for a convenient timing reference for vertical scanning. PAL countries, which 127 00:09:40,940 --> 00:09:46,290 have 50 hz electricity, have a television frame rate of 25 frames per second interlaced, 128 00:09:46,290 --> 00:09:52,360 with a scanning refresh rate of 50 hz. So, tv framerates are what they are because convenience. 129 00:09:52,360 --> 00:09:56,480 So now that we have the means to generate this raster, well how does that make a picture? 130 00:09:56,480 --> 00:10:00,660 Well, it’s just like the POV effect from the toy, only it’s a helluva lot faster 131 00:10:00,660 --> 00:10:05,320 and the light moves in two dimensions. Let’s slow down time and see how the TV builds an 132 00:10:05,320 --> 00:10:10,950 image. Let’s say we want to show this on the screen. At the start of a field, the deflection 133 00:10:10,950 --> 00:10:15,130 yoke is pointing the electron beam at the top left of the screen. As it moves towards 134 00:10:15,130 --> 00:10:19,290 the right, the beam changes its intensity along with how bright the image should be, 135 00:10:19,290 --> 00:10:23,230 so at a point along the line that’s bright, it produces a lot of electrons, and thus that 136 00:10:23,230 --> 00:10:28,410 point on the screen glows brightly. Dark parts send little to no electrons. When the beam 137 00:10:28,410 --> 00:10:31,830 gets to the end of the line, the deflection yoke almost instantly pulls it back to the 138 00:10:31,830 --> 00:10:36,779 left-hand side and starts the next line. But remember, it skipped a line. This process 139 00:10:36,779 --> 00:10:40,700 repeats until it reaches the bottom of the screen. Then the yoke flings the beam back 140 00:10:40,700 --> 00:10:45,360 to the top, and we start again filling in the alternate lines. This happens way too 141 00:10:45,360 --> 00:10:49,550 fast for us to notice it, so it appears like a fully illuminated screen. 142 00:10:49,550 --> 00:10:53,649 One thing to note is that the vertical deflection isn’t happening in steps. Rather it’s 143 00:10:53,649 --> 00:10:58,100 a constant downward motion. This means that the horizontal lines are actually slightly 144 00:10:58,100 --> 00:11:03,050 slanted downward to the right. To counteract this, the deflection yoke is mounted to the 145 00:11:03,050 --> 00:11:07,721 tube ever so slightly crooked, so the lines drawn on the screen are actually level. The 146 00:11:07,721 --> 00:11:12,649 constant downward travel is also how the interlacing is accomplished. The next line will start 147 00:11:12,649 --> 00:11:16,410 at the same height as the end of the first, which creates a gap. 148 00:11:16,410 --> 00:11:20,220 You may remember an extremely high-pitched noise coming from a TV set whenever it was 149 00:11:20,220 --> 00:11:25,149 turned on. This noise actually came from the deflection yoke and the electronics that drive 150 00:11:25,149 --> 00:11:31,820 it. In NTSC televisions, the horizontal deflection occurred 525 times per frame, and there are 151 00:11:31,820 --> 00:11:37,500 30 frames in a second, which means the electron beam is being deflected left-and-right 15,750 152 00:11:37,500 --> 00:11:43,240 times per second. In PAL countries, the framerate is only 25 frames per second, but 625 lines 153 00:11:43,240 --> 00:11:48,700 are drawn with each frame, which works out to 15,625 deflection per second. The yoke 154 00:11:48,700 --> 00:11:52,580 and the flyback transformer, along with some other components, actually vibrate at this 155 00:11:52,580 --> 00:11:57,990 frequency ever so slightly, which produces audible noise. This is what it sounds like. 156 00:11:57,990 --> 00:12:01,959 Adults over the age of 25 or so can’t hear this sound, as it’s at the upper limit of 157 00:12:01,959 --> 00:12:07,420 human hearing range, which gradually diminishes with age. So for those viewers, sorry. 158 00:12:07,420 --> 00:12:10,970 When it comes to actually producing an image, the trickiest part is matching that raster 159 00:12:10,970 --> 00:12:15,630 to an incoming television signal. To help with this, the TV signal contains triggers 160 00:12:15,630 --> 00:12:20,330 which assist the TV in grabbing hold of the image and keeping it in one place. 161 00:12:20,330 --> 00:12:23,920 This Sony TV is correctly tuned to channel 3, which is currently displaying this video 162 00:12:23,920 --> 00:12:29,330 that you’re hearing right now. But there’s absolute nonsense on the screen. What gives? 163 00:12:29,330 --> 00:12:33,640 Well, the TV is generating its own raster, and right now it’s not synchronized with 164 00:12:33,640 --> 00:12:37,980 the raster coming into the TV. You’re seeing all of the image, but each part is in the 165 00:12:37,980 --> 00:12:42,670 wrong place because it’s not lined up. Here, to show you what the TV’s looking for, let’s 166 00:12:42,670 --> 00:12:46,910 fade to white. You’ll notice that there are a ton of black gaps swirling around what 167 00:12:46,910 --> 00:12:51,700 should be an entirely white screen. These gaps are the horizontal blanking intervals 168 00:12:51,700 --> 00:12:57,160 between individual scanlines. When horizontal hold is properly adjusted, electronics in 169 00:12:57,160 --> 00:12:59,950 the TV can see these gaps and line them up. 170 00:12:59,950 --> 00:13:03,660 Hold up, how can the set tell the difference between the blanking intervals and a black 171 00:13:03,660 --> 00:13:08,560 spot on the screen? Well, it can tell them apart because the blanking intervals are actually 172 00:13:08,560 --> 00:13:14,420 BLACKER THAN BLACK. No, really. Here’s a one line of a television signal drawn on a 173 00:13:14,420 --> 00:13:18,620 graph. These parts at the ends are the blanking intervals between scan lines. They are the 174 00:13:18,620 --> 00:13:23,459 lowest parts of the graph because their amplitude is near zero. Here is the actual start of 175 00:13:23,459 --> 00:13:27,590 the scan line. The higher the line goes, the brighter that part of the scan line will be 176 00:13:27,590 --> 00:13:33,190 drawn on the screen. Makes sense, but black is all the way up here. Television sets are 177 00:13:33,190 --> 00:13:38,120 calibrated to not fire the electron gun at amplitudes at or below this amount, so to 178 00:13:38,120 --> 00:13:42,910 they eye, any amplitude below this point won’t be visible, but the electronics can clearly 179 00:13:42,910 --> 00:13:47,110 tell blanking intervals from signals. The blanking interval isn’t there just to provide 180 00:13:47,110 --> 00:13:51,459 a reference for the beginning and end of a scan line, it’s also there prevent anything 181 00:13:51,459 --> 00:13:55,660 from being drawn on the screen as the deflection yoke sweeps the electron beam back to the 182 00:13:55,660 --> 00:14:01,079 left-hand side before the start of the next line. The TV just has to line these low points 183 00:14:01,079 --> 00:14:04,930 up by catching them at the beginning of each scan line, and then they’ll fall into the 184 00:14:04,930 --> 00:14:08,019 TV’s own raster. Everything is hunky dory. 185 00:14:08,019 --> 00:14:12,080 So then, when I adjust the horizontal hold, you can see that this moves the blanking intervals 186 00:14:12,080 --> 00:14:17,831 closer to each other, and eventually, the image snaps into place. well, sort of. Now 187 00:14:17,831 --> 00:14:22,920 the image is rolling, it’s continually moving downwards. Ah, see, we have only synchronized 188 00:14:22,920 --> 00:14:27,279 the television's raster with the horizontal components of the signal. Without a reference 189 00:14:27,279 --> 00:14:32,540 as to what starts a field scan, the pictures just gonna roll around like this. See that 190 00:14:32,540 --> 00:14:36,589 hunk of black between my head and my waist? That’s the vertical blanking interval, which 191 00:14:36,589 --> 00:14:41,290 is little more than a bunch of empty scan lines. Just like the horizontal intervals, 192 00:14:41,290 --> 00:14:45,431 it allows the deflection yoke time to get back to the top of the field. Again, this 193 00:14:45,431 --> 00:14:50,470 is BLACKER THAN BLACK, and it allows the television to hold onto the start of each field and keep 194 00:14:50,470 --> 00:14:55,570 them in one place. The vertical blanking interval also contains some special pulses to differentiate 195 00:14:55,570 --> 00:14:57,260 between the odd and even numbered fields. 196 00:14:57,260 --> 00:15:01,230 So, i’ll adjust the vertical hold, and eventually, the frame snaps into place, and you get a 197 00:15:01,230 --> 00:15:06,649 truly stable image. Very intentionally, the CRT is scanning outside the borders of the 198 00:15:06,649 --> 00:15:11,100 face of the tube. This is called overscan, and it’s done to hide the blanking intervals 199 00:15:11,100 --> 00:15:15,400 as well as just ensure the whole screen is being used. On this set, you can see how the 200 00:15:15,400 --> 00:15:20,940 scan extends beyond the tube itself when looking from behind. This unseen overscan area was 201 00:15:20,940 --> 00:15:25,760 used later to add closed captioning into television broadcasts. On one of the lines that make 202 00:15:25,760 --> 00:15:31,040 up the VBI, alternating white-black bits created a barcode of sorts that contained digital 203 00:15:31,040 --> 00:15:36,290 text information. A decoder inside the television set could read this data from that line, and 204 00:15:36,290 --> 00:15:40,529 when enabled place text graphics on top of the image. I think that’s pretty friggin 205 00:15:40,529 --> 00:15:41,529 nifty. 206 00:15:41,529 --> 00:15:45,380 As far as audio, well that’s really simple. That’s nothing more than simple FM radio 207 00:15:45,380 --> 00:15:50,139 built into the TV, and each channel has an audio signal being transmitted at a set offset 208 00:15:50,139 --> 00:15:54,450 frequency from the video source. Since the signals are transmitted together, they are 209 00:15:54,450 --> 00:15:55,450 always in sync. 210 00:15:55,450 --> 00:16:00,060 So, that’s how these old things work. But there’s a lot more to explore. For one, 211 00:16:00,060 --> 00:16:04,459 how did television cameras actually create the signal that drives this TV? And who were 212 00:16:04,459 --> 00:16:10,860 the people responsible for inventing it? What about color? We’ll explore that in a later episode, along with 213 00:16:10,860 --> 00:16:15,640 the precursor to CRT television, mechanical television, so be sure to subscribe to Technology 214 00:16:15,640 --> 00:16:19,709 Connections. If you liked this video, I humbly ask that you hit that like button and maybe 215 00:16:19,709 --> 00:16:23,920 leave a comment. I’m doing my best to keep videos like this headed your way. Thanks for 216 00:16:23,920 --> 00:16:26,240 watching!