Degradation of a fluorescent material used in an image display device provided with an electron emitting device that is caused by heating in the process of manufacturing the device is prevented. A unit shifts the frequency of components of the audio signal above a frequency threshold value only. The position of the beacon signal shifts within each beacon period based upon a predetermined pseudo-random sequence. The single-piece insulator unit has embedded channels to provide electrical connectivity between the circuitry, The entire assembly is placed in housing and a cap assembly having prongs to connect to a AC wall outlet is ultrasonically welded to the housing. Such visual alerts may comprise icons or graphical advertising units that may be navigated by the subscriber to trigger and initiate corresponding and dynamically updatable communications and communication links.