The Repeater Units are a main quest item in Wasteland 2.
A plain black box on the outside, but who knows what's going on inside?
There are a total of two repeater units which were being carried by Ace, in order to learn more about the mystery signal of Matthias. They are a necessary item to further advance the storyline of the game.
Both the repeater units are found on the cadaver of the dead synth located in a cave at the western edge of the Radio Tower.