1 00:00:00,160 --> 00:00:07,440 Maybe it's just because I'm old, but even though Spotify, podcasts, and other 2 00:00:05,120 --> 00:00:11,679 forms of audio streaming seem to rule the day, there's just something 3 00:00:09,440 --> 00:00:15,440 comforting about the simplicity of turning a knob on the radio and 4 00:00:13,440 --> 00:00:20,240 listening to what's happening on the airwaves. Even in the digital age, radio 5 00:00:18,400 --> 00:00:25,760 has maintained a fair amount of popularity since the first public 6 00:00:22,560 --> 00:00:28,800 broadcasts in the early 20th century. 7 00:00:25,760 --> 00:00:31,199 But since radio has been around since 8 00:00:28,800 --> 00:00:36,800 long before we had things like digital decoders that turn electrical impulses 9 00:00:33,360 --> 00:00:39,360 into music, how the heck do simple cheap 10 00:00:36,800 --> 00:00:44,079 radios know how to convert an electromagnetic radio signal into a I 11 00:00:42,320 --> 00:00:49,840 don't know, let's say a basketball game or a weather report or a you know Justin 12 00:00:47,840 --> 00:00:55,840 Bieber's greatest who put that crap in my script. Anyway, AM radio broadcasts 13 00:00:53,520 --> 00:01:02,320 showed up before FM. So, we'll start with those. An AM station will broadcast 14 00:00:58,879 --> 00:01:04,960 a signal at a constant frequency, but 15 00:01:02,320 --> 00:01:10,720 will add the soundwave representing the actual audio to that base signal. It's 16 00:01:08,240 --> 00:01:15,840 also called a carrier wave, resulting in the height or amplitude of the wave 17 00:01:13,280 --> 00:01:21,600 changing accordingly. This is where the term AM comes from, as it stands for 18 00:01:18,799 --> 00:01:28,240 amplitude modulation. You can get your radio to play back this signal as actual 19 00:01:24,560 --> 00:01:29,920 music or dialogue by tuning it to 20 00:01:28,240 --> 00:01:34,960 whatever frequency the station that you're looking for broadcasts at. This 21 00:01:32,720 --> 00:01:39,840 makes your antenna resonate at the frequency and ignore everything else in 22 00:01:37,520 --> 00:01:45,200 the air. So, very simple radio tuners are actually little more than coils of 23 00:01:42,720 --> 00:01:50,240 wire. How many turns of the wire will determine what frequency you're picking 24 00:01:47,280 --> 00:01:54,399 up. Cool, right? The antenna actually creates an electrical current that 25 00:01:52,079 --> 00:01:58,479 corresponds to the radio signal. This current is sent to other parts of your 26 00:01:56,479 --> 00:02:03,040 radio that filter out the irrelevant parts of the signal and send it to your 27 00:02:00,719 --> 00:02:08,239 speakers or your headphones as changes in voltage which drive those speakers 28 00:02:05,680 --> 00:02:12,800 and produce sound. It's actually pretty remarkable that this is all done without 29 00:02:10,399 --> 00:02:19,760 any digital decoding by something like a a CPU. It's a completely analog process 30 00:02:17,040 --> 00:02:26,000 that made it possible for news, music, and entertainment to stream into homes 31 00:02:22,239 --> 00:02:28,160 decades before the internet or even TV. 32 00:02:26,000 --> 00:02:32,239 FM broadcasting works somewhat similarly, though with FM, it's the 33 00:02:30,480 --> 00:02:38,720 frequency of the signal that gets changed, hence the F in FM. FM radios 34 00:02:36,640 --> 00:02:44,319 have a special transformer inside them that basically sits idle as long as 35 00:02:41,680 --> 00:02:48,800 exactly whatever frequency you're tuned to hits your antenna. But once it 36 00:02:46,879 --> 00:02:53,040 detects a small change in that frequency, it outputs a voltage that 37 00:02:51,120 --> 00:02:59,920 makes your speakers emit a certain sound. So let's say you're tuned to 99.5 38 00:02:56,480 --> 00:03:02,319 FM on your dial. Since FM works by using 39 00:02:59,920 --> 00:03:10,400 very small changes in frequency to carry a signal, you are actually tuned to 40 00:03:05,280 --> 00:03:12,560 signals just above and below 99.5 MHz, 41 00:03:10,400 --> 00:03:18,000 which makes that transformer send the voltage to your speakers. Now, although 42 00:03:15,360 --> 00:03:24,159 this process makes FM more complicated to engineer than AM, you often get a 43 00:03:20,959 --> 00:03:26,400 much clearer, higher quality signal. FM 44 00:03:24,159 --> 00:03:31,360 is less susceptible to interference as well because interference often 45 00:03:28,239 --> 00:03:34,400 manifests as amplitude spikes. An AM 46 00:03:31,360 --> 00:03:36,400 radio would see these spikes as actual 47 00:03:34,400 --> 00:03:40,959 sound to produce and it would end up coming out of your speakers while FM 48 00:03:38,720 --> 00:03:45,760 cares about variations in frequency rather than amplitude. So an FM radio 49 00:03:43,440 --> 00:03:49,440 can just ignore that type of interference and the death metal you're 50 00:03:47,760 --> 00:03:55,920 listening to will come out sounding just as clear and angry as ever. FM also has 51 00:03:54,159 --> 00:03:59,840 the advantage of having much higher bandwidth than AM due to the 52 00:03:57,599 --> 00:04:05,599 mathematical properties of frequency modulation. This allows for lots of 53 00:04:02,959 --> 00:04:11,599 wiggle room in the signal to create more sounds more accurately, making FM the 54 00:04:08,720 --> 00:04:15,599 clear choice for music, while AM is often just fine for stuff where 55 00:04:13,280 --> 00:04:22,240 highfidelity isn't a big deal, such as talk radio. But if FM is so superior, 56 00:04:18,880 --> 00:04:25,840 then why do AM stations seem to have so 57 00:04:22,240 --> 00:04:28,160 much better range? Well, it's because AM 58 00:04:25,840 --> 00:04:33,040 wavelengths are much longer, meaning that they can move more effectively 59 00:04:30,960 --> 00:04:37,840 following even the curvature of the Earth and deal with obstacles like 60 00:04:35,520 --> 00:04:43,440 buildings, whereas you can quickly lose highfrequency FM signals if you start 61 00:04:40,560 --> 00:04:48,400 putting stuff in the way. AM frequencies also allow signals to cause free 62 00:04:45,680 --> 00:04:53,440 electrons in the ionosphere to oscillate at the same frequency as the radio wave 63 00:04:50,800 --> 00:04:58,479 that hits them. Meaning that AM signals can actually reflect off the upper 64 00:04:55,919 --> 00:05:02,479 atmosphere. At night, there are more free electrons hanging out in the sky, 65 00:05:00,320 --> 00:05:06,960 which is why you can sometimes hear AM stations from hundreds of miles away 66 00:05:04,880 --> 00:05:12,320 after the sun goes down, as opposed to FM, which tends to go right through the 67 00:05:09,520 --> 00:05:15,840 atmosphere. Of course, this may not seem impressive when the internet allows you 68 00:05:14,000 --> 00:05:20,000 to listen to highquality digital broadcasts from the other side of the 69 00:05:17,520 --> 00:05:25,440 world, no problem. But good old analog radio still has the distinct advantage 70 00:05:22,080 --> 00:05:28,400 of only requiring a $10 receiver with no 71 00:05:25,440 --> 00:05:33,039 subscription fees and very high ease of use, especially for people who might not 72 00:05:30,639 --> 00:05:36,960 be terribly tech-savvy. And of course, your radio will keep working even if 73 00:05:35,199 --> 00:05:43,440 your finicky internet connection goes out. Sometimes simpler is indeed better. 74 00:05:41,520 --> 00:05:47,600 Speaking of keeping things simple, FreshBooks. Freshbooks is the 75 00:05:45,520 --> 00:05:53,759 cloud-based accounting solution that helps you, you small business owner, you 76 00:05:51,360 --> 00:05:58,000 keep organized, get more work done, and ultimately, well, make more money. 77 00:05:56,160 --> 00:06:02,080 Because what FreshBooks does is it lets you track your expenses by taking 78 00:06:00,080 --> 00:06:06,639 pictures of your receipts, track your hours on particular jobs through the 79 00:06:04,240 --> 00:06:12,000 cloud interface, send bills to your customers through the app itself, and 80 00:06:09,680 --> 00:06:16,400 even take payments from your customers via credit card directly through 81 00:06:14,319 --> 00:06:20,639 FreshBooks. With all that stuff in one place, whether you're a plumber or a 82 00:06:18,319 --> 00:06:25,680 small-time computer repair operator or you do, I don't know, TV installations, 83 00:06:23,280 --> 00:06:30,080 whatever it is you're doing, it allows you to spend your time doing that 84 00:06:27,919 --> 00:06:33,919 instead of staring at complicated accounting software at the end of every 85 00:06:31,680 --> 00:06:38,639 day when your brain is tired because you were working on other stuff and you just 86 00:06:36,319 --> 00:06:44,160 don't feel up to it. The best part is you can try FreshBooks for free for 30 87 00:06:41,360 --> 00:06:47,759 days by going to freshbooks.com/tequicky which is linked in the video description 88 00:06:45,680 --> 00:06:51,440 and entering techquicki in the how did you hear about us section. So thanks for 89 00:06:50,319 --> 00:06:54,720 watching guys. If you like the video like it. If you disliked it, dislike it. If you want to check out our other 90 00:06:53,520 --> 00:06:58,000 channels, boom, we got a link right there. If you want to leave a comment with suggestions for future fastest 91 00:06:56,880 --> 00:07:03,199 possibles, you can do that below. And as always, don't forget to subscribe and follow and all that good stuff. See you 92 00:07:00,720 --> 00:07:03,199 next time.