Practical COMSEC Practices: Part 5 - Signal Control (Directional Antennas)

Поделиться
HTML-код
  • Опубликовано: 4 фев 2025

Комментарии • 6

  • @moga864
    @moga864 24 дня назад +1

    Enjoyed the discussion. Thank you sir.
    And that reminds... that I need another HT pouch from the catalog. Yours are truly far and away the best I've found on the market in terms of quality of materials, durability, and overall craftsmanship.
    I hope you guys always maintain that high standard. It's hard to find these days.

  • @radioguy19510
    @radioguy19510 23 дня назад

    A beam antenna acts just like a flashlight in that tha farther you get from the antenna the wider the signal. At VHF and UHF frequencies, there is no way to make that beamwidth so that you can direct a signal to one specific point but if both beams are in the vertical plane thay have the narrowest beamwith on the ground.. A omni antenna is like a lightbulb on a table and radiates just the same.Another thing to consider is with beam antennas is that you want to transmit in the same plane (especially when using low power) that is to say that both antennas should be vertical or horizontal. You can lose a lot of signal if they are cross polarized.

  • @BobBob-il2ku
    @BobBob-il2ku 17 дней назад

    There’s one element to small unit communications that usually gets
    zero attention- antenna polarization. Let’s take a look at our most common
    denominator at the basic level- the Baofeng UV-5R. Its a VHF and UHF
    FM two-way radio. FM nearly always uses vertical polarization, meaning in
    simple terms, the antenna is straight up and down. In a conventional environment we do this for two reasons. First,
    pretty much everyone else is vertically polarized when communicating via FM, and second, there’s 9db of loss between a vertical polarization and
    horizontal polarization. Wait, what? With each 3db of gain, we double our effective radiated power (ERP) in terms of signal
    strength. With each 3db of loss, we cut our strength in half. This is
    measured in orders of magnitude, meaning that with each 3db, the strength
    doubles on itself (4w x 2= 8w x 2= 16w, etc). Taking that into account, the
    difference in strength between horizontal and vertical polarization is 9db-
    quite a difference. If someone is using a vertically polarized antenna to
    attempt to intercept my transmission, they’d likely be using vertical
    polarization. After all, why wouldn’t you? Nearly all FM transmissions are
    vertically polarized, its common practice. But if I change my operating
    practice to account for this, now they’re going to have a harder time both
    intercepting and getting a bearing on me. Not impossible, mind you. But much harder. And that’s on top of my
    other operating practices, such as transmitting on one frequency and
    receiving on another, keeping my transmissions as short as possible, and making sure I’m always using directional antennas. It goes without saying
    that your intended receiving station should be matched in polarization.

  • @protow5178
    @protow5178 24 дня назад

    After covering these basics how about something a bit more tricky?

    • @moga864
      @moga864 24 дня назад

      "The whole purpose of these videos is just to give YOU some ideas to do some research and some things to look into"
      🤦‍♂️

    • @KS6DAY
      @KS6DAY  24 дня назад +1

      I will definitely be expanding on all of these topics going forward. Just laying the foundation with this series.