3 watts AM transmitter circuit diagram and calculation needed

Discussion in 'Wireless & RF Design' started by bizzie, Feb 10, 2010.

  1. bizzie

    Thread Starter New Member

    Feb 10, 2010
    Please i need a very urgent help on a mini project: the design and construction of a 3 watts AM transmitter. What i really need is the circuit diagram and every neede calculations , then i would do the construction on my own. Any help would be apprecited. I have less than 24 hours to submit. Thanks
  2. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
    I think you have to answer a few questions first:

    1) What will the carrier frequency be?
    2) Will it be crystal controlled or free running?
    3) Will it be high level modulated, with a Class C r.f. amplifier or low level modulated with a linear amplifier? (Two ENTIRELY different methods)
    4) Will you be using bipolar transistors, FET's or even vacuum tubes?
    5) What will be the bandwidth of the audio applied?
    6) What will be the percentage of modulation?
    7) How many R.F. stages do you expect to use?
    8) How many audio stages do you expect to use? Will these be discrete, or can you use op amps?
    9) Do you plan on using any audio transformers?
    10) If you are using high level modulation, will you use conventional analog methods or PWM?

    I've been designing transmitters for nearly 40 years, and even I can't do what you request without more information.

    Just so you know.

  3. bizzie

    Thread Starter New Member

    Feb 10, 2010
    Thanks for your reply.It should be low-level modulated, with bipolar transistors, crystal controlled. Every other requirements you can furnish it . What i mean is that use whatever carrier frequency you want ,little number of rf stages.Thanks
  4. bertus


    Apr 5, 2008

    The carrier frequency is the center frequency where the transmitter is working.