Hardware used: Raspberry pi Zero W
Github repo: https://github.com/markondej/fm_transmitter
Some reasons to build this are to have your own radio station, to research radios, or if you're pirate operator sharing for others
To get started building this you are going to need to get a microsd card and flash it with RaspbianOS. The reason why I chose Raspbian is since its meant for the raspberry pi and is lightweight. If your flashing it using the offcial raspberry pi imager then it might be best to do whats called a headless install that way you can just ssh into the pi without having to plug anything in beside power. After flashing it put it into the raspberry pi and power it on then give a minute or so to install. When its done connect to raspberry pi using ssh or hdmi with a mouse and keyboard and run the following commmands below to begin the install.
sudo apt update && sudo apt upgrade -y
sudo apt install git make build-essential libraspberrypi-dev
git clone https://github.com/markondej/fm_transmitter
cd fm_transmitter
make
Boom you are done making your own FM radio station if you want to test it run the following and change whats in the <>: sudo ./fm_transmitter -f