Hey, i did this "3 Stages FM Transmitter" on project board & got result. It tuned at 91.3 MHz (frequency vary all the time).
But the problem is to calculate the oscillating frequency at the 2nd stage(Q2, oscillator circuit).
If i use
L = (d²n²) / (18d+40l)
(Where L is the inductance of the coil in uH, d is the coil diameter in inches, l is the coil length in inches and n is the number of turns.)
and f=1/(2π√LC)
then the frequency i got is not in the range of FM, its almost around 200 MHz.
(Coil L1 comprises four turns of 20SWG enameled copper wire wound to 1.5cm length of a 4mm diameter air core &
Coil L2 comprises six turns of 20SWG enameled copper wire wound to 2.1cm length of a 4mm diameter air core.)
I attached the circuit diagram. Someone help me pls, i know you guys are really helpful.
Thanks
But the problem is to calculate the oscillating frequency at the 2nd stage(Q2, oscillator circuit).
If i use
L = (d²n²) / (18d+40l)
(Where L is the inductance of the coil in uH, d is the coil diameter in inches, l is the coil length in inches and n is the number of turns.)
and f=1/(2π√LC)
then the frequency i got is not in the range of FM, its almost around 200 MHz.
(Coil L1 comprises four turns of 20SWG enameled copper wire wound to 1.5cm length of a 4mm diameter air core &
Coil L2 comprises six turns of 20SWG enameled copper wire wound to 2.1cm length of a 4mm diameter air core.)
I attached the circuit diagram. Someone help me pls, i know you guys are really helpful.
Thanks
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