WEBVTT 1 00:00.000 --> 00:02.320 Alright, let's do some math. 2 00:02.320 --> 00:08.560 So remember, our starting point is always 0 dBm equals 1 milliwatt. 3 00:08.560 --> 00:12.880 And then we just have to take one of these sides to whatever we were given. 4 00:12.880 --> 00:15.240 So in this case, we're given 13 decibels. 5 00:15.240 --> 00:19.120 To get there, we'd say plus 10 and plus 3. 6 00:19.120 --> 00:21.520 So that gets us to our 13. 7 00:21.520 --> 00:27.160 Meanwhile over here, plus 10 means that, remember, we multiply by 10 and plus 3 8 00:27.160 --> 00:27.920 is multiply 9 00:27.920 --> 00:29.120 by 2. 10 00:29.120 --> 00:33.440 Our rule of 10s is plus 10 is multiplied by 10. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 10 00:29.120 --> 00:33.440 Our rule of 10s is plus 10 is multiplied by 10. 11 00:33.440 --> 00:35.960 Minus 10 is divided by 10. 12 00:35.960 --> 00:38.840 Plus 3 is times 2. 13 00:38.840 --> 00:41.200 Minus 3 is divided by 2. 14 00:41.200 --> 00:45.420 So this would be our set of rules that we're going to use throughout this set 15 00:45.420 --> 00:46.440 of examples. 16 00:46.440 --> 00:50.840 So if I'm multiplying 1 by 10, and then by 2, this would be 20. 17 00:50.840 --> 00:53.600 And so the answer is simply 20 milliwatt. 18 00:53.600 --> 00:54.920 So let's do the same thing down here. 19 00:54.920 --> 00:56.680 We start with our 0. 20 00:56.680 --> 01:00.280 We start with our 1 to get to 24. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 20 00:56.680 --> 01:00.280 We start with our 1 to get to 24. 21 01:00.280 --> 01:03.080 I could do a bunch of 3s. 22 01:03.080 --> 01:04.520 That would be one way to do it. 23 01:04.520 --> 01:11.080 I could also get to 30 and then go backwards to 27 and then to 24. 24 01:11.080 --> 01:17.600 So I could say plus 10 plus 10 plus 10 and then minus 3 minus 3. 25 01:17.600 --> 01:25.000 So this would be times 10 times 10 times 10, which this is 1000. 26 01:25.000 --> 01:27.560 And then divided by 2 divided by 2. 27 01:27.560 --> 01:33.600 So that takes me to 500 and ultimately 250 milliwatt. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 27 01:27.560 --> 01:33.600 So that takes me to 500 and ultimately 250 milliwatt. 28 01:33.600 --> 01:34.840 Now what if you did the other way? 29 01:34.840 --> 01:38.440 What if we said, hey, I'm just going to add 3 8 times. 30 01:38.440 --> 01:44.400 So if I'm adding 3 8 times, that would be times 2 times 2 times 2 8 times. 31 01:44.400 --> 01:48.200 So that would be 2 to the 8th power, which is 256. 32 01:48.200 --> 01:49.200 So wait a second, Jeff. 33 01:49.200 --> 01:52.800 Why doesn't that equal the exact same thing? 34 01:52.800 --> 01:59.380 And the answer is because even though a plus 10 dBm is exactly equal to a times 35 01:59.380 --> 02:00.560 10 milliwatt's WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 35 01:59.380 --> 02:00.560 10 milliwatt's 36 02:00.560 --> 02:06.240 plus 3 is actually more like 0.1995, something like that. 37 02:06.240 --> 02:10.200 We actually estimate around a little bit with the rule of 3s. 38 02:10.200 --> 02:14.970 So the more 3s we use, the more it's going to be a little bit inaccurate with 39 02:14.970 --> 02:16.160 the conversion. 40 02:16.160 --> 02:19.160 But for the most part, again, we see it's about the same thing. 41 02:19.160 --> 02:22.160 A 6 milliwatt difference isn't a major difference. 42 02:22.160 --> 02:27.080 And so either one of these could be considered the correct answer. 43 02:27.080 --> 02:29.960 Now from here, 200 milliwatt's to how many decibels. 44 02:29.960 --> 02:31.880 So now we're flipping it around a little bit. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 44 02:29.960 --> 02:31.880 So now we're flipping it around a little bit. 45 02:31.880 --> 02:36.400 I'm going to start with my 1 milliwatt equals 0 decibels. 46 02:36.400 --> 02:42.000 And I've got to figure out how to get to 200 using these rules. 47 02:42.000 --> 02:49.120 So if I could get to, let's say, times 10 is 10, times 10 is 100, and then 48 02:49.120 --> 02:50.200 times 2, well, 49 02:50.200 --> 02:52.920 that does get me to 200. 50 02:52.920 --> 02:57.740 And times 10 is equal to plus 10, times 10 is equal to plus 10, times 2 is 51 02:57.740 --> 02:59.440 equal to plus 3. 52 02:59.440 --> 03:02.080 And so the answer here is going to be 23. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 52 02:59.440 --> 03:02.080 And so the answer here is going to be 23. 53 03:02.080 --> 03:04.840 So 23 dBm. 54 03:04.840 --> 03:06.280 And then lastly, our 25. 55 03:06.280 --> 03:13.480 So same concept, I'm going to start with 1 milliwatt equals 0 decibels. 56 03:13.480 --> 03:16.120 Now I have to get to 25 using 10s and 2s. 57 03:16.120 --> 03:21.230 But first, this seems kind of impossible. I mean, how do I get from 1 to 25 by 58 03:21.230 --> 03:21.400 multiplying 59 03:21.400 --> 03:22.720 by 10 and 2? 60 03:22.720 --> 03:24.480 I just can't do that. 61 03:24.480 --> 03:27.680 But in the same way with the decibels, I can go forward and backwards. 62 03:27.680 --> 03:32.360 For example, I could say times 10 times 10, and then this gets me to 100. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 62 03:27.680 --> 03:32.360 For example, I could say times 10 times 10, and then this gets me to 100. 63 03:32.360 --> 03:37.650 Well, now I can kind of see a path to get to 25, because I could say divide by 64 03:37.650 --> 03:38.320 2 to get 65 03:38.320 --> 03:42.280 to 50, and then divide by 2 to get to 25. 66 03:42.280 --> 03:49.880 So this would be plus 10 plus 10 on the decibel side, and then minus 3 minus 3. 67 03:49.880 --> 03:53.920 And so at this point, it would be 20 minus 6. 68 03:53.920 --> 03:57.440 And so the answer here is 14 dBm. 69 03:57.440 --> 04:01.650 So this is a set of examples that gives us a good look at how to perform our WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 69 03:57.440 --> 04:01.650 So this is a set of examples that gives us a good look at how to perform our 70 04:01.650 --> 04:03.560 decibel math. 71 04:03.560 --> 04:06.880 And we just need to really keep in mind this table right here. 72 04:06.880 --> 04:11.110 If we can remember the rule of 10s, remember the rule of 3s, that's going to 73 04:11.110 --> 04:11.560 help us to 74 04:11.560 --> 04:15.000 be able to do the conversion, whether we're given a decibel that we need to 75 04:15.000 --> 04:16.720 convert to millawatts 76 04:16.720 --> 04:20.560 or vice versa, we're given millawatts that need to convert to decibels. 77 04:20.560 --> 04:21.560 A decibels. 78 04:21.560 --> 04:24.640 I hope there's been informative for you, and I'd like to thank you for viewing.