This is a circuit diagram for radio transmitter suitable for installation in a series of radio transmitting collars. This circuit is work with based on 555 timer and JFET. This is the figure of the circuit.
The pulse in the FM band between 88 MHz to 105 Mhz, which can be adjusted. Ne IC 555 are cable as astable multi vibrator to produce tone.L1, C3 and Q1 form a modulator. End of Q2 to the power amplification. For inductors made of 5 rounds, he was 5 mm insulated copper wire on a standard ball pen refill. Remove the refill and making a tap on the center coil varies transmission frequency. To experiment with the number of turns. Careful!!! What might once have had to turn the tap on center. Use 50 cm long insulated copper wire as an antenna.
Part:
R1…………………………………. 10K
R2 …………………………………1 M Ohm
R3 ………………………………….330 Ohm
R4 …………………………………..1 M Ohm
R5……………………………………. 330 Ohm
R6 ……………………………………200 Ohm POT
C1 ……………………………………..0.1 uF Ceramic
C2…………………………………….. 0.01 uF Ceramic
C3…………………………………….. 13 pF Ceramic
C4, C5, C6, C7 ……………………..0.01 uF Ceramic
Q1, Q2 ………………………………..2N4392 JFET
D1 ……………………………………….1N 914 Diode
IC 1……………………………………… NE 555
