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  1. #1
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    How to use 100Mhz oscillator output to get audio sound on FM radio?

    i have a little oscillator that outputs 100 mhz, so how can i do to mix an audio sound to that frequency for listen to it on a simple FM radio ?
    thanks

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  2. #2
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    Re: 100Mhz oscillator

    I am afraid that 100MHz oscillator is not suitable for this application ..
    What you need is a small FM modulator and here is an example:
    http://www.electronics-lab.com/proje...012/index.html
    Regards,
    IanP


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  3. #3
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    Re: 100Mhz oscillator

    I assume you mean for reception on an FM radio. You need to vary the frequency of the 100 MHz oscillator in proportion to the audio signal. If there is a voltage control for frequency tuning, you can tune the oscillator with that. It is possible to also tune the oscillator (in a much more crude fashion) by AC coupling the audio signal onto the oscillator power supply pin. For instance, put a 47 ohm resistor between the oscillator Vcc pin and the supply, then put a 1 uF series cap between the oscillator Vcc and your audio source.

    You may have to vary the audio level to keep it from distorting in the radio. And, I assume that you are not using a crystal 100 MHz oscillator, which will not tune enough no matter what you do to it.


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  4. #4
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    100Mhz oscillator

    thanks guys for help, the problem is that is a crystal 100 Mhz oscillator so as a solution i will take a VCO from an old VHF VCR/TV tuner and i will inject audio signal to the VT pin



  5. #5
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    Re: 100Mhz oscillator

    You could try an armstrong modulator with the crystal:

    http://www.see.ed.ac.uk/~gjrp/EE3/Co...e10/sld006.htm



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