am transmitter

Discussion in 'Wireless & RF Design' started by emnel, Jun 1, 2012.

  1. emnel

    Thread Starter New Member

    Feb 20, 2012
    2
    0
    hi i try to design wireless mic using AM technique but m stack.first i try to design an oscillator for 1MHz cause crystall are not available here and im using LM741,for a wein bridge oscillator also on Modulator i'm using MC1496
    help me out guys.
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,348
    Hello,

    A wienbridge oscillator at 1 MHz with a LM741 will not work.
    The gain is not enough to keep the oscillator running at 1 MHZ.

    The following page of the EDUCYPEDIA will give you a lot of info about analog modulation techniques:
    http://educypedia.karadimov.info/electronics/modulation.htm

    Bertus
     
  3. absf

    Senior Member

    Dec 29, 2010
    1,493
    372
    Is this a school project or just for hobby cause I see the word "design". How far you want your transmitter to go or how many "mW" you want it to be?

    Was the reason to use op-amp to make the oscillator cause you want to get rid of the inductor? Or else there are simpler circuits making use of transistors on the net and why dont you just start from there? Here's one I found that's quite simple ....:D

    http://www.zen22142.zen.co.uk/Circuits/rf/amtx.htm

    Allen
     
  4. emnel

    Thread Starter New Member

    Feb 20, 2012
    2
    0
    the project is school project , i want my transmitter to transmit to 30m ,
    on mW please help me out cause i have a little knowledge on it.
     
  5. absf

    Senior Member

    Dec 29, 2010
    1,493
    372
    Did you try the circuit that I attached in the link? I supposed it should fulfill your requirements.

    30m is not that far so if the transmission doesnt reach that just increase the length of the aerial or change Q2 to an RF transistor with higher P(tot) characteristics on the output. The circuit was well explained and there is a calculator for you to determine the frequency if you decided to change the value of L1, C1 and L2,C2.:)

    Allen
     
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