Yes I've noticed that sometimes on digital equipped televisions but not with set top boxes or devices with cablecards up in Northern Jersey on other cable providers where they use a dedicated EAS channel. From what I've been told, Comcast usually uses a standard channel available on all service tiers such as QVC or a local channel. The reason for this is for equipment that do not support a "forced tune event" (when a device such as a set top box, or DTA, or TiVo recieves a specific signal it automatically tunes to a designated channel for the duration of the alert then tunes back to whatever channel it previously was on). Equipment such as televisions that do not support the "forced tune event" will generally show a banner or ticker across the top or bottom of the screen or even a full screen message (slate) prompting the viewer tune to that designated channel, such as "Please tune to Channel 19 for more information" or "Please tune to your emergency alert channel for further details". This has fallen out of favor for the more recignizable full screen message (slate) such as the black screen with white text or blue screen with white text and red border, which includes the full alert. This incorporates who sent the alert, what the alert is, the location or affected area of the alert, when the alert ends, and the callsign of the provider such as a PEP radiostation ie WRAT-FM or cable provider ie comcast