Building Modulating circuit

cableguy44

Member
Apr 23, 2004
28
0
0
Need some help. I have thought of a project for myself. I would like some input. I am going to try to make a circuit that can take my cd player output and modulate it on a frequency in the FM band so that I can listen to it in my work truck that doesnt have a tape deck. So here is what I came up with that I will need:
1 oscillator at desired output frequency
1 modulator, is FM mixer the same thing????
1 amp circuit
1 filter circuit

Any suggestions or any ideas on the schematic, I would appreciate it before I get started. My main question is, is an fm mixer basically just a modulator.
 

IamElectro

Golden Member
Jul 15, 2003
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0
76
It would be cheaper to buy one in the long run. If you look around you can find one powered off the cigarette lighter for 20-30 bucks.
Building one is possible but a simple unit will not broacast in stereo.
 

harrkev

Senior member
May 10, 2004
659
0
71
If you use a regular mixer, you will get an AM transmitter. The usual method of creating FM is to use a PLL circuit. You can add your desired signal to the error signal (after error goes through a low-pass filter). Then, you run the output of the PLL oscillator through a suitable RF amp to an antenna.

This is not a job for a beginner.