FM bug Spy transmitter
Take a look at this fm spy transmitter which can be used as a bug transmitter or as fm bug too. It uses a single IC 74F13, one coil, a capacitor, one trimmer, one resistor and ofcourse one electret mic. This spy bug is so easy to build and can give you a total coverage range of about 3 to 5 meters. You may want to use a small 100mW amplifier to give a little extend transmission range so you can spy from other location.
Please use only 74F13 because 74S13 and the other ones does not work in 88-108MHz range. As antenna you can use a copper wire (>=1mm diameter) and as power supply 4 x1.2 / min.1200mA acumulators which will work for at least 7 days. Use short terminal for components and a good pcb.
Mini bug FM spy transmitter circuit
about 4 months ago
how many turns is the coil?
about 4 months ago
It is a choke coil but you can use 20 turns on a ferrite core. The coil is not so much important in this bug transmitter circuit.
about 4 months ago
Thanx marius
about 4 months ago
ha ha
about 4 months ago
Peter, may I ask you why are you laughing? Is there something funny in the fm transmitter diagram or in the comments section?
about 3 months ago
thev three capacitors are they 1nf or 1mf ,33nf or 33mf or 33pf , 100nf or 100mf pls i need help
about 3 weeks ago
hello..
for this circuit, how about the receiving end? does this circuit transmit at specific frequency? thanks
about 3 weeks ago
“Use only 74F13 because 74S13 to work in 88-108MHz range” – so use a FM receiver.