Below mention transmitter is very simple to assembled ,
which is consist of only 2 transistors (
2SC2407 & 2 SC3950 ) having a stable frequency & with a high power
(Range) is a tough task to do , actually you can buy a high power FM
transmitter , but hard to make it due to the restriction as well as parts
availability in the certain areas , in my this circuit the input were taken
from the Car MP3 modulator , antenna point at the PCB can be easily found ,
where they always printed the every point on the PCB , if not found the antenna
point then you can use the field strength
meter (FSM) , antenna will be the
peak FSM reading , this signal were then given to the circuit , sometime the RF
power from the MP3 found low which cannot derive the first transistor , for this biasing required
from positive supply to the transistor base to boost some hove the input signal
, 30 k to 56 k resistor can be used for the biasing ,in first stage I used
2sc2407 transistor ,in the final stages 2sc3950 were used , very cheap
transistors ,where all these transistor can work very nice in the FM range, RFC
were used at the transistor collector which can be easily available in the
market RFC for FM rage will be 0.56
mh or 0.68 mh (Micro henry) you don’t have to wound the coil , 2-30 PF Variable capacitor ofr fixed 20 PF capacitor can be used, also you can
use 2N2219 , 2N3866, 2N2222 instead 2sc2407 , also you can use 2sc1971 , 2n353
instead of 2sc3950.
