Simple radio beacon

Discussion in 'Wireless & RF Design' started by masteropie, Jan 22, 2010.

  1. masteropie

    Thread Starter Member

    May 17, 2008
    26
    0
    I am designing a simple radio beacon for 28mhz.

    What is the simplest oscillator? I look for an ic, i think a vco (pll?) would work, easy to adjust with trim pot. The problem is when the battery runs down the frequency will shift so it needs a zener regulator, complicated.

    How much voltage swing do i need on the antenna to get 5w output. 12v/50ohms=240ma*12volts = 2.9W (no good). I have never understood this.
     
  2. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
    2,040
    287

    I think you'd be better off with a crystal oscillator like a Pierce. If the voltage drops below a certain level, it will just quit.\

    Why do you need any more than 2.9 watts for a beacon. Especially for 10 meters. (I trust you have a license for this)

    eric
     
  3. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    Go through old CB circuits, they are nothing but simple 27Mhz oscillators, 1 transistor and a crystal.
     
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