what is an rf modulator used for
RF modulator. An RF modulator (or radio frequency modulator) is an electronic device whose input is a baseband signal which is used to modulate a radio frequency source.
What is an In-Car FM Modulator? An in-car FM modulator is just a radio frequency modulator that is specifically designed for use in a car audio system. Radio frequency modulators are essentially just workaround devices that were originally designed to allow external components to be hooked up to televisions and home radios.