A unitary jack assembly to facilitate monitoring, testing, maintenance, and installation of audio and visual systems as well as telecommunication systems which utilize coaxial cables for signal transmission. The jack assembly comprises a unitary housing having two coaxial jacks extending outwardly from the front thereof which are electrically connected to two corresponding coaxial connectors extending outwardly from the rear of the housing. A third coaxial jack extends outwardly from the front of the housing and is electrically connected to one of the other two coaxial jacks. A switch is carried within the jack assembly housing and is normally electrically connected to the first and second coaxial jacks and is further adapted to ground the signal in one of the jacks when the other jack has an electrical plug inserted therein.