Thread: Is this a headend issue?

In a specific town there is an ongoing issue at 471MHZ and Its been boggling my mind trying to understand whats causing it. Intermittently the picture goes to a black screen on 471meg but you can still hear the audio perfectly clear. At first I immediately thought some noise kicking back on the system but it didnt make sense that the audio was still there and not choppy or breaking up. Anyway I did a sweep throughout and no ingress. Also did a FM deviation to see if I can actually hear anything at 471 still nothing. Ive never seen it in another town so it is possible its specific to that node, but its a new issue so its still possible its going on througout a whole corp. Any ideas?

Analog or digital at 471? Direct connect or through STB? In the 471 range I believe there is land mobile communication, 2-way radio traffic. Could it be a leak? I use to see this in HAM radio spectrum, or in local police radio freqs, and it would wipe the video only, or if real bad the entire channel would be gone for as long as the transmission would last. When it happens how long does it last for?