I want circuit for FM Radio Transmitter and FM Radio Receiver

Discussion in 'Wireless & RF Design' started by honest, Dec 16, 2009.

  1. honest

    Thread Starter New Member

    Dec 16, 2009
    4
    0
    Hi all.
    I want to build 2 radio phones communicate with one another, when I speak from radio phone1 I hear my voice from radio phone2.
    so I want circuit for FM Radio Transmitter and FM radio Receiver

    so, the radio phone1 transmits the voice like "hi" and radio phone2 receive the same voice "hi"
    Please help me
     
  2. honest

    Thread Starter New Member

    Dec 16, 2009
    4
    0
    please help me
     
  3. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    FM receivers are a lot harder than FM transmitters. My suggestion is to build a simple transmitter, then use a cheap commercial receiver.
     
  4. steinar96

    Active Member

    Apr 18, 2009
    239
    4
    What is your knowledge of electronics ?. Designing them yourself with little knowledge is going to be a very difficult task.
     
  5. honest

    Thread Starter New Member

    Dec 16, 2009
    4
    0
    I love the invention so I want to build it by myself
     
  6. honest

    Thread Starter New Member

    Dec 16, 2009
    4
    0
    Please I want explain parts this FM transmitter circuit
    [​IMG]


    what's the mean C9 100pF
     
  7. ShadowReaper

    New Member

    Feb 1, 2009
    5
    0
    Read a book about electronics and then ask
     
  8. steinar96

    Active Member

    Apr 18, 2009
    239
    4
    The comment above is a bit harsh. But there is small truth in it however. The circuit you want described is actually quite complex, especially for someone with little or no understanding of electronics and it's unlikely that someone will take attempt to explain it since it will be many pages and alot of time spent trying to explain it fully. There are good books on this subject, most likely you are going to have to spend some time to acquire the knowledge needed.
    If you still want to pursue these rf circuits i recommend you get your hands on a amateur rf communications book. There are plenty of good ones about.
     
  9. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    Just a suggestion, look up any HAM (AKA, amateur radio) clubs in your area. These are exactly the kind of people you want to query, and they do what you're wanting to do now as a matter of course. We have a lot of HAMs on this site, I'm one. What part of the world are you? The odds are good you can find what you need locally, and receive instruction on the laws concerning these transmitters in your area so you can do it legally (always a plus).
     
  10. PRS

    Well-Known Member

    Aug 24, 2008
    989
    35
    Q1 is the input amplifier for your voice. This feeds Q2, which is a mixer. The mixer combines the audio signal from Q1 with an rf signal created by Q2. The rf frequency is 1/(2*pi*sqrt(C*L1)) where C =C2//C3 and C3 is for tuning purposes. Note the oscillator in the collector of Q2 and its 360 degree feedback into Q2. C6 limits the feedback so that the oscillator has a gain of just above 1 volt per volt.
     
    Last edited: Dec 30, 2009
Loading...