Hak5 1604 – Carrier Waves, Amplitude and Frequency

Modulating Carrier Waves with Amplitude and Frequency, plus the relationship between Wavelength, Frequency and the speed of light. All that and more, this time on Hak5.

Download HD | Download MP4



  • Steve

    Lets try this again.
    A carrier wave sine wave is a transmitted signal without modulation,
    A cycle is from one point on the wave to the next same location along the wave for example see (8:22). This measurement point can be from positive peak to positive peak, negative peak to negative peak or crossover point to crossover point( like and an “S” on its side.

    The amount of time it takes for the wave complete one cycle is called the period.. If it take 1 second to complete one cycle its considered 1CPS (Cycles Per Second) or 1 Hertz. A 2 Hertz signal will take only 1/2 second (.5 seconds) to complete 1 cycle.

    In an AM (Amplitude Modulated) signal, if you could draw a line from peak to peak across the entire transmission you will have the wave of the audio used to modulate it. The source data used to modulate the carrier wave also called the intelligence, which is kind of an oxymoron because not all is.

    Good job guys, Have a great day

  • Netcat

    Daren make an oopsie, that is not a cycle. As Steve had noted.

    Neat little picture.

    As I learned it. A copper wire breaking a magnetic field will cause a flow of electrons.
    Zero is in between North and South. You get a Half Circle when that wire rotates on a generator shaft.
    Then Zero South to Zero South/North you get the other half circle.
    Simply you are seeing a circle measured over time. Thus you get the “wave” form that you have drawn.

    Daren please be more careful next time.


  • Mike C.

    FWIW, the speed of light does change, based on the material it’s traveling through. It’s speed through a vacuum is constant, but even space isn’t a *complete* vacuum.

  • Philip McC

    I agree with netcat. It is time to beat up Darren about his information THIS time. 🙂
    1. Image the cycle as a circle… It ends at the same point it starts at. In this case on the vertical axis, it would be crossing at ‘0’.
    2. The speed of c (of light) in a vacuum is roughly what you specific. It is a constant in a vacuum. When it passes through certain materials, it slows down.

    For Both… an interesting thing you may remember from Star Trek and the Borg. Remember when they had to modulate their shield frequency to prevent the Borg weapons from penetrating. So… remember, at certain wave-lengths we are transparent. In our visual spectrum, we reflect most of those wavelengths. In other wavelengths, we are opaque. —
    Physically you can block radio waves because they are literally too large to fit through the opening.
    Think of a Faraday cage. The holes in the mesh would determine which wavelengths can pass through.

  • YoMamma

    Great show i love the getting to the fun-de-mentals and very visceral practicalities of da tech! Keep it up. Post Script Awesome comments!

  • CedrickZBlazing

    Thank you, I have just been searching for information approximately this topic for a long
    time and yours is the best I’ve came upon so far. However,
    what concerning the conclusion? Are you certain concerning the source?

  • CaseyPHect

    What’s up i am kavin, its my first occasion to commenting anyplace, when i read this post i thought i could also create
    comment due to this sensible post.

  • CandraMTibbles

    Someone necessarily lend a hand to make severely posts I would state.
    That is the very first time I frequented your web page
    and up to now? I surprised with the analysis you made to make this actual publish amazing.
    Wonderful activity!

  • Young

    Hello, i think that i saw you visited my weblog so i came to “return the favor”.I am attempting to find things
    to enhance my site!I suppose its ok to use a few of your ideas!!

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>