Wireless Microphone Circuits

FM Wireless Mike: low power frequency modulated transmitter using two transistors. The circuit works with 9v power supply. . (Circuit added 9/04)

Low-power FM Wireless Microphone: Small, wireless microphone that will transmit a whisper to a nearby (1/4 mile radius) FM radio, tuned to the 100 - 108 Mhz region of the dial. Powered by 9-volt battery, and features hand-wound inductor. This Detailed Description contains theory of operation, construction tips, and some testing procedures. (circuit design added 10/06)

Micro Spy With FETs: (Electronic Schematic / circuit added 4/02)

Micro Spy With TTL: (Electronic Schematic / circuit added 4/02)

Micro Spy With USW: (Electronic Schematic / circuit added 4/02)

Miniature FM Transmitter: (Electronic circuit added 4/05)

Miniature FM Transmitter #1: (Electronic Schematic / circuit added 4/02)

Miniature FM Transmitter #2: (Electronic Schematic / circuit added 4/02)

Miniature FM Transmitter #3: (Electronic Schematic / circuit added 4/02)

Miniature FM Transmitter #4: (add 9/04)

Miniature FM Transmitters #5: (added 6/03)

Miniature MW Transmitter: circuit diagram of simple medium wave transmitter using BF494B. This simple transmitter have a range of 200 meters. . (Circuit added 9/04)

Wireless Microphone #4: (Electronic circuit added 4/05)