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FM Transmitter with voice recorder. Answered

This is what I would like to have made. I see these in spy websites for cheap. I don't want to spy on anyone but need for for another reason. Can anyone here on this site point me in the right direction.

It's a short range FM Transmitter that has a built in voice recorder for up to 4 minutes made.

The recorder would have a simple button that you would press to record with a built-in mic and small speaker for playback. The recording when transmitting would loop forever.

The unit would be powered by a small battery and solar panel or just solar panel if that would work both indoors and out. The unit would only have to transmit during daytime hours.

I would need the FM Transmitter to transmit no more than 100 feet and to meet FCC for USA. The transmission would need to be a very clear transmission because it is going to be used for advertising. It does not need to be in stereo.

I've attached an image of what I would like to have made and the case is available at http://www.polycase.com/




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7 years ago

They sell a lot of them on ebay VERY CHEAP. not worth building. Record whatever you want as an MP3 onto an SD card. plug the SD card into the unit and set it to play back each file randomly or sequentially. If you only have ONE file to repeat...just set it to repeat mode. I used mine to transmit music throughout a metal building. it worked great. I opened the unit up and found where the transmit antenna was, and I lengthened the wire for better range. It transmits in stereo. some people have difficulty finding a CLEAR spot on the dial to transmit on. If you set it to transmit JUST BELOW the FM band... at 87.5 MHz, you can really receive it clearly... but NOT ALL FM radios can tune to 87.5. Here is a link to one on ebay similar to the one I used. :


Hope that helps.