vcc ---------------------------------------
| | |
| | -------
C R L VC
| | -------
| | |
a----------- ----------------K
|
|
gnd --------------------------------------
The circuit show above is a oscillator i made for fr transmitter. I used 2n2222 transistor L is inductor - i just make a few turn from wire, VC is veriable capacitor. R i used 200 ohm and capacitor c 0.01u. for vcc i used 9v. Hire i not sure about the frequency but when i tune near a radio i get a sound when i turn a VC. For transmiting a data i just pull out the cap c and connect the uc with data signal at point a. The modulation it used now is ook on off keying. now i working for receiver circuit if it work i will write in this forum.