Mini FM transmitter

660

05:29:23

From the schematic http://cie-wc.edu/FREEKItPlans.aspx

I cant get my real life version to work so i'm throwing it up here to analyze it. 

     *  Light represents Microphone
     *  cap parallel to inductor is suppose to be a trimmer so you can set the radio station then adjust trimmer to find correct value.

 
                    1
f =       _____________
                       ______
             2pi   v/  LC

(you never would have go that picture if i wasnt high right now  >:p)

(frequency equals the reciprocal of 2 times pi times the square root of the product of L times C) 

So with the current values transmission should happen at about 100.6 FM

published 10 years ago

Neeh

10 years ago

Gheghe, nice one. Check out mine, which, although quite crappy, does work in real life! ;)

Neeh

10 years ago

http://everycircuit.com/circuit/5105600212500480

diode76

10 years ago

Nice

thebugger

10 years ago

These things are awfully unstable. I made one of these in 20min and it took me to tweak it (not perfectly) 40min. Plus there are enormous amounts of parasitic effects that disturb the oscillator. The oscillator/modulator, should be separated (buffered) from the antenna and the power stages.

hurz

10 years ago

Video and circuit link - have fun with this little qimmik http://youtu.be/3hoBb_BWZMk http://everycircuit.com/circuit/5061577535389696

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