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  • W8MI! Whiskey right Mexico IndiaDennis, do you read me?

  • Can I just, like, text you next time? This is weird...

  • Can you read me DNews, what's your 20?

  • Sciencemen Trace here hamming it up for DNews.

  • Remember that time Eleven needed to talk to Will in the upside-down?

  • The kids were excited because they got to use a ham radio.

  • Ham radio is an amateur radio broadcasting system -- people who operate ham radios are

  • called "hams!"

  • There are nearly three million ham licenses worldwide: with major populations of hams

  • in Japan, Germany, England, Indonesia, South Korea.

  • According to the National Association for Amateur Radio, there are more than 727,000

  • licensed ham radio operators (called hams) in the U.S. -- making us the second largest

  • community.2

  • I say community, because that's what amature operators says it's all about.

  • Ham radios are exactly like any other radio, but instead of your local rock, country, or

  • Beyonce station playing nothing but the hits, nothing but the hits

  • Instead, it's Jenny from the block, Sloan from Canada, or Siso from Swaziland; right

  • there, in your radio!

  • Aside from the fun community aspect, in times of disaster, when cell towers and internet

  • are down, hams can still communicate with each other and emergency services.

  • All radio works the same, even ham radio.

  • When electricity travels through an antenna of some kind, another antenna can pick it

  • up and decode it.

  • Tune a radio to a static AM station, grab a nine volt battery and a coin, hold them

  • near the antenna and connect the studs with the coin.

  • The radio will pick something up!

  • The electricity is "broadcasting" radio5.

  • The battery will only go a few inches, but with more power, the signal can go farther.

  • Thanks to advances in technology, we can pinpoint exact frequencies to broadcast on, where the

  • radio waves are precisely tuned so they don't interfere with each other.

  • According to HowStuffWorks, ham bands are "above the AM radio band (1.6 MHz) to just

  • above the citizens band (27 MHz) (also known as CB radio!)"

  • And on those ham bands, the FCC says people can send 1,300 different types of communication

  • using voice, video, digital, telegraphy (morse code!)... you name it -- it's all shared space,

  • though.

  • So if someone else is using that frequency, it becomes a party line.

  • There are three main Ham radio bands: HF, VHF, and UHF.

  • With UHF or "ultra high frequency" the waves leave the antenna and bounce off buildings

  • and around solid things, but can't go2 around mountains.

  • VHF "very high frequency" waves can pass around some obstacles, but can still be blocked.

  • These are mainly "line of sight" antennas.

  • Straight lines.

  • Think FM radio.

  • Which is why it doesn't work over the curve of the Earth or behind a mountain.

  • But, that doesn't stop all radio.

  • HF "high frequency" waves are my favorite in this scenario

  • Because, starting about 50 kilometers above you is the ionosphere -- an electrically charged

  • layer of the atmosphere.

  • Ham radios using the HF range can bounce their waves off the ionosphere, creating a Sky Wave.

  • That wave "skips" to another point on the Earthor hits another antenna -- which

  • might rebroadcast it!

  • All ham signals can be rebroadcastsomeone can pick it up, and send it out again.

  • Like a relay!

  • I wasn't kidding when I said Swaziland!

  • But Swaziland isn't the furthest radio can reach.

  • In 1969, an operator in Louisville, Kentucky picked up radio between Armstrong and Aldrin

  • on the moon during Apollo 11.

  • He even recorded President Nixon's message to them!

  • You can still talk to astronauts with amature radio today.

  • The ionosphere doesn't bounce all signals!

  • On the International Space Station, the crew has access to a ham radio.

  • When they're overhead, their 2-meter FM transceiver allows the ground can have a chat with space.

  • You can see for yourself that the astronauts are overhead, talk to them while they're there,

  • and then they fly away.

  • TAKE THAT

  • If you're fascinated by how far afield ham radios can reach, the new CW show, Frequency

  • takes that even further.

  • In the show, a female police detective in 2016 discovers she can reach her estranged

  • father over the airwaves of her ham radio.

  • Plot twist: He's in 1996!

  • Don’t miss the Series Premiere of Frequency, Wednesday October 5th, at 9/8c only on The

  • CW.

  • It's pretty amazing that we can do all this with waves of electromagnetic energy.

  • The more you think about it, the cooler it gets.

  • Which is why DNews Plus did a whole thing on LIGHT!

  • What is it anyway?!

  • Wait, what?

  • You don't know DNews Plus?

  • It's like DNews, but ten times longer.

  • We take a big topic, like Artificial Intelligence, Leaving Earth, or Light -- and get nerdy with

  • it.

  • If you're smelling what we're cookin' subscribe to DNews Plus on YouTube, or listen to it

  • as an audio podcast on Soundcloud or iTunes.

  • Have you ever tried a ham radio?

W8MI! Whiskey right Mexico IndiaDennis, do you read me?

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如何在家中與太空人對話? (How You Can Talk To An Astronaut From Home)

  • 127 9
    李柏毅 發佈於 2021 年 01 月 14 日
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