AskATech
join:2009-10-16
Keansburg, NJ
| 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? |
|
heels_fan
1.20.09 The start of Socialism
Premium
join:2003-02-07
Columbia, TN | is it happening in just one node or is it system wide?
Do you have a spectrum analyzer? |
|
AskATech
join:2009-10-16
Keansburg, NJ
| at this point its hard to say ive heard people saying they have seen it througout the system but up until today ive only seen it in one node....today i saw a very similar issue in a completely different node in a different corp and it seemed more like an ingress issue today cause both audio and video dropped out but I do have a spectrum analyzer and swept from 300 to 500 meg and it was absolutley clean again...the one today happened to have ingress in the sub band, but ive had it were it was clean everywhere...i recently heard police and fire use a new frequency up there...and the house i was in today the guy was a police officer with a scanner and everything so im wondering if the noise is bleeding through right at the cable box....that might explain why I am not seeing nething when I sweep on my spectrum analyzer |
|
Madison
WI
join:2002-02-07
| 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?
--
So many cat's..too few receipies |
|
burner50
Pinlifter
Premium,VIP
join:2002-06-05
EN22wm
 ·Mediacom
 ·FrontierNet Intern..
| reply to AskATech
»www.radioreference.com/apps/db/?cs=WIL630
»www.radioreference.com/apps/db/?cs=WIK851
Possible Culprits? I'm not familiar with the area, but those frequencies would be smack between the chroma and video carriers and could potentially leave the audio carrier alone?
Unless we're talking about a digital feed, then it would be a headend issue.
--
I'm tired of killing stupid people just trying to do my job and go home! |
|
cableguy
Premium
join:2009-01-20 | reply to AskATech
Do you guys have some of your channels on SDV Switched Digital Video? I've seen this in Orlando and it turned out to be a problem with our SDV provider.
--
GIT R DONE |
|
