Long Range FM Transmitter Schematic Diagram

RF Radio circuits | By: Diagram mania

This circuit uses transistor T1 (BF494), a VHF oscillator transistor with output power 50mW and transistor T2 (2N3866), an A-Class VHF transistor. Variable resistor VR1 converts oscillator’s basic frequency, whilst VR2 is used to control the power. Power output from this circuit is quite small, it is because this circuit doesn’n’t have amplifier. This circuit works optimally by adding RF amplifier and antenna. Here is the schematic diagram :

Long Range FM Transmitter Circuit Diagram

Parts list :

  • Diode D1 : BB109
  • Resistor R1 : 10k ohm
  • Resistor R2 : 100k ohm
  • Resistor R3 : 180k ohm
  • Resistor R4 : 4K7
  • Resistor R5 : 15k ohm
  • Resistor R6 : 68 ohm
  • Resistor R7 : 470 ohm
  • Resistor R8 : 39k ohm
  • Resistor R9 : 10 ohm
  • VR1 : 47k ohm
  • VR2 : 22 ohm
  • Capacitor C1-C3, C8 : 0.1 uF
  • Capacitor C4 : 4.7 pF
  • Capacitor C6 : 0.01 uF
  • Capacitor C7 : 5.6 nF
  • Capacitor C9 : 100 pF
  • Transistor T1: BF494
  • Transistor T2:2N3866
  • Trimmer VC1-VC2 : 50p
  • L1 : 4 round 20 cables SWG in plastic with 8mm diameter
  • L2 : 2 round 24 cables SWG
  • L3 : 7 round 24 cables SWG in plactic with 4mm diameter
  • L4 : 7 round 24 cables SWG in ferrid bead

Estimated price : $8