This is a low power consuming fm transmitter with a decent range of 30 meters. Talking about the applications of this project we go into the spy area again. This circuit can be used to listen conversations from 30 meters away, or it can be adjusted to transmit the phone line. I am sure you can find many other applications, its your imagination.   Main advantage of this circuit is that power supply is a 1.5Volts cell (any size) which makes it possible to fix PCB and the battery into very tight places. Transmitter even runs with standard NiCd rechargeable cells, for example a 750mAh AA size battery runs it about 500 hours (while it drags 1.4mA at 1.24V) which equals to 20 days. You will find full info and schematics on authors page.

FM transmitter using a single transistor and with 30 meters rangeFM transmitter using a single transistor and with 30 meters range schematic

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