I’m running wire for an addition, and wonder if power wires (12-2 and one huge hunkin one that feeds the whole house) would cause interference in the coax. Specifically, I would like to run the coax in the same holes in the joists that the power runs through.
The coax are feeds from satellite TV and satallite internet.
That certainly can cause interference and even induce unwanted voltage on the coax. Also, in some areas, it may be a code violation for Class 2 (eg: coax, phone, network cables) to share the same holes and passages as power wiring.
If you have to run power and signal wiring parallel to each other, run the signals a foot away from the power wherever they’re parallel. It’s OK for them to be close together when they cross at right angles.
Should be ok. Powerline frequencies are MUCH lower than the RF carried by the coax, and are usually cut off by the radio or TV equpiment’s front end circuitry anyway. Running audio cable along power lines, OTOH, almost invariably results in 60-Hz hum, and so should be avoided. RF cabling is generally immune to 60-Hz interference, though. There may, however, be some interference caused by noisy digital equpment connected to the circuit. If you see regular interference patterns in your video, turn off electronic devices such as computers, monitors and printers one by one until the interference goes away. Then try plugging the offending device into a different circuit. Snap-on ferrite chokes can also cut down or eliminate digital hash interference. Put them on the load end of the power cable of the noisy device, as close to the device as possible.