Ok, a few postings as I have been gone from this blog for a year. Reboot.
Above is a pic of a simple FM transmitter that picks up ambient sound in a room, such as talking, and transmits it at a frequency that can be picked up by any FM radio. Less than 20 simple parts, it works amazingly well for such a simple circuit. It contains one transistor and a microphone I salvaged from an old FRS radio. The silver wire coil is handmade, just a piece of wire coiled around a pen. This is not my invention nor is it anything new, but it is quite an effective short-range transmitter “bug” that I’m sure has been replicated thousands of times by amateur “spies.”
Posted in Electronics and Radios by Mark with .