We received a notification regarding signal leakage on our door yesterday afternoon. Since we weren't home for the tech to fix the issue, my husband called and scheduled an appointment for later this week. What exactly is signal leakage, what causes it, and what should I expect during the service call?
Thank you Jay! Our cable was not disconnected, and since we set up an appointment so quickly I'm assuming we won't be disconnected. We have had service through Comcast in this location for 6 years and this is the first time we have received this type of notification, so it must be a recent development if signals are checked yearly.
A RF cable system is kind of like the water pipes in your home, there can't be any leaks. The coax cable has a center conductor that carries the RF signals, and there is a multi-layer aluminum shield on the outside of the coax cable to keep those signals from leaking out. Damage with the coax cables, rubbing on the coax, and mostly, poorly installed / corrorded / loose F connectors (fittings) will cause leakage, along with cheap splitters, and cheap drop amplifiers.
Leakage can affect both the downstream signals from the local node feeding the RF portion of your neighborhood, and the upstream return signals that come back from cable modems & eMTA phone adapters and cable set top boxed / DVR's.
Leakage can affect neighbors for blocks around, ingress can be from electrical equipment interference getting into the RF system. Downstream leakage can cause interference with public saftey and aircraft frequencies, thus the FCC demands every cable systems to be swept for leakage once a year, usually by aircraft with highly sensitive equipment to detect leaks. Sometimes, neighbors report issues with HSI, CDV and On Demand which the tech finds leakage from others causing the problems. Sometimes, subscribers unknowing hookup the coax to their TV antenna, broadcasting to the whole neighborhood. Many times, in high density buildings it is caused by "illegal" hookups from neighbors hooking up to other's coax to receive TV without paying for it, and those splices leak.
The tech will have a leakage detector to sweep near where the coax cable runs in the house, and visually inspect fittings, and condition of the coax cable looking for damaged shielding.
Sometimes when a house is found to be leaking badly, the drop gets cutoff until repairs have been made, and a tag is put on the front door, and a call from the cable co to tell the sub of the issue.