Radio bug
Difficulty: ★★★☆☆
Time: About 2 hours
From scrap: ██░░░░░░░░ 20%
PreambleWhat can I say, I made a tiny radio transmitter to spy on somebody, I want to share the experience. It works perfectly
Materials- The electret microphone, any of the tape player or phone
- A piece of the wire for the antenna
- All in the scheme
Tools- Soldering iron
- Scheme
Radio transmitter could be assembled on prototype plate or PCB - Coil
Coil has 5-6 turns of wire thickness of 0.5 mm. I wined it around gel-pen rod. By tension and compression coil is adjusted to the desired frequency of the receiver and then fix coil with superglue. - Antenna
Antenna is an insulated piece of wire - Capacitor
Put a 0.01 uF capacitor between the poles of the power supply (9 volt) to protect your diy radio transmitter against interference.
How to make a radio transmitter
Results and tips- Super clear sound from 15 meters distance, I can hear ticking clock
What could be replaced - С4 and С5 could differ up to 2-3 pF
- С6 could differ up to 10 pF
- VT1 could be replaced by КТ315, КТ342 or КТ3102, BCW72
- VT2 could be replaced by any low-powered n-p-n transistor with frequency of single amplification not more than500 MGz (КТ368, КТ316)
