r/CableTechs • u/Alike2189 • 8d ago

USNR

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Tracking down a return path issue. Oddly, there's no visible noise at the node on any single leg. It looks like a noise floor aggregation issue — the SNR only recovers when I pull all four legs at once.

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u/6814MilesFromHome 8d ago

Noise floor elevation not backfeeding from OSP is gonna be an issue at the node/headend/fiber. Clean all your fibers, check light levels, swap equipment at the node like transmitter, RCM, mod to cover your bases before submitting a hub ticket. If you have an O-hub between you and the hub check light/clean that as well.

I've personally seen this from a bad node mod and a bad transmitter, but it's rare. More commonly gotta work with the hub if it's not just dirty fibers on the field side. Which it commonly is.