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asdasd12345
01-06-2007, 05:07 PM
i am trying to build a transmitter that transmits an audio signal that i could just pick up with a normal radio. i want to try and figure it out by myself instead of using someone elses schematic. i understand i will need some kind of oscillator, but what i dont understand is how do i get the signal from a microphone and then mix it into the oscillator. this part confuses me.

beenthere
01-06-2007, 06:26 PM
Hi,

Google on topics like "signal mixer" and "carrier modulation". Look at the ARRL site for information. You will need to have some understanding of radio before you can expect to have much success designing radio circuitry.

mrmeval
01-06-2007, 07:14 PM
One transistor transmitter
http://www.geocities.com/tomzi.geo/1-transistor/1-transistor.htm
http://members.tripod.com/~transmitters/begin.htm

Two transistor transmitter
http://www.zen22142.zen.co.uk/Circuits/rf/2bjttx.htm
http://www.geocities.com/tomzi.geo/2-transistor/2-transistor.htm

3Watt FM transmitter
http://www.aaroncake.net/circuits/3Wfmtran.htm

Four transistor amplifier
http://www.zen22142.zen.co.uk/Circuits/rf/4txtr.htm

There are others