Coaxial One Way Filter?

[HarryMuscle]

Is there such a thing as a coax one way filter? I've been troubleshooting a cable modem issue and I've determined it's a branch of my house coax cabling that seems to be acting as an antenna and introducing noise into all the other cables every few hours including the cable connected to my modem. The simple solution would be to disconnect the "bad" cable but I have a TV connected there. So I was wondering if there's such a thing as a one way coax filter that would allow TV signals through but prevent any signals in the other direction. Searching for one way coax filter doesn't bring up any such products.

 

[KsWoodsMan]

If that line is acting as an antenna picking up strong local signals then it's probably also is RADIATING signals from the coax.
While this might not be a problem for you directly it does cause noise and interference on the US Aircraft band.
The FCC has strict regulations for this type of interference. I'd recommend correcting the problem by replacing the bad coaxial cable or at the very least having new connectors installed.
Your local cable company might even be willing to assist with this so planes in your area aren't hindered from communicating by the interference caused by a leaky cable TV coax.

 

[degrub]

Most cable issues are termination issues. I would redo those first unless you can find physical damage or have access to a time domain reflectometer.

a quick test might be to lay in a separate temporary coax run and disconnect the offending cable.

you were able to rule out the TV itself ? Or other loose or corroded ground/shield connections ?