According to Ramsey Electronics, an FM radio transmitter, or broadcaster, allows you to connect any audio device such as a microphone, computer or MP3 player via a line output or tape-out connector to the transmitter and broadcast whatever is playing on the audio device on a frequency modulation (FM) signal. This FM signal can be picked up and broadcast by any FM radio within a certain radius of the transmitter – some FM transmitter kits are powerful enough to have a broadcast range of 1/4-mile, under certain weather conditions.
Purchase a FM radio transmitter kit. These kits vary in price, depending on their strength and complexity levels. As of December 2010, the advanced-level Super Pro FM Stereo Radio Station Kit retails for £175.4, whereas, the entry-level FM10C FM Stereo Transmitter Kit retails for £29.20.
Find a workspace where you can layout the printed circuit board and all of the circuit components from your kit. Lay out the schematics for your kit, so you can easily identify where each component will go on your printed circuit board. The board will also have markings that help you to identify where the components go.
Use fine-grain sandpaper and lightly clean the leads, which are the metal pins that insert into the printed circuit board of each circuit component.
Bend the leads and insert them into the holes of the printed circuit board. If the leads are too big for its holes, use a mini-drill to make the holes bigger.
Solder the components to the board. Use a fine-tip, lightweight hot iron with power set to no more than 25 Watts. Tack the leads into the board by using the hot iron to melt a piece of solder wire over the on top of where the top of the leads emerge from the board. It should take approximately five seconds to tack each lead to the board.
Install the completed FM transmitter. Following the directions appropriate for your kit, install the transmitter’s circuit board, which you assembled in steps 3 through 5 into the transmitter’s housing or box.
Insert all other components, such as the microphone, knobs and all other items that complete the kit. Use a screwdriver, or the appropriate tool, to complete the assembly of the transmitter’s housing.