By Rob Beschizza at 4:35 am Mon, Mar 23, 2009
Implied: “We’re assuming you’re too stupid to actually specifically rebroadcast our signals so we’ll hold off on cutting your cable off, but we had better not find a transmitter when we come to fix it.”
RF leakage is a real problem for cable companies and they spend a lot of money each year combating it. The leakage can appear anywhere, from a broken cable in the ground to an unterminated cable in your home. The main issue with leakage is that it is two way. Yes the cable signal can leak out, but RF signals can leak in. This causes very real, and very annoying issues for multiple customers as the interference can disrupt TV, data, and telephone service.
Mnemonic, does that mean if you pumped a strong enough signal into the cable, you could broadcast over the top of what your neighbors are watching?
Signal leakage from cable television systems poses interference issues for amateur radio operators, as well.
Additionally, once a cable operator is made aware of their leak, by their own detection or otherwise, they are required to fix it.
They almost certainly don’t suspect the cable customer of malice or actual wrongdoing in this case, but they will probably need to enter the customer’s home, hence the letter.
This is not a fun situation, I’m sure, but it’s not entirely Comcast’s fault, although according to the link, they are handling it in a less-than-graceful manner, which is entirely their fault.
I’m curious – is there more to this letter, or was that it?
Time to take it to Sears for a “Recharge”. I like to have mine topped off every month.
Or you can do it at home with the Plasma recharge Home Kit.
Adam, click the letter to read it all!
I can’t believe no one’s made a “It’s coming from INSIDE THE HOUSE.” joke yet.
Where I live in Seattle, I’ve heard they will do yearly flyover with a aircraft equipped with a special signal detector that will show hot spots of signal leakage in neighborhoods. Quite often it comes from cheap cable, poorly compressed fittings and consumer signal amplifiers.
To answer #3’s question, I don’t believe it would work that way. If your signal was leaking strong enough to be detected by your neighbor’s analog antenna, you might see some ghosting on the local channels.
I’m suprised it’s taken them that long to fix the problem. I’m assuming the area they live in is serviced by mainly contractors, who just do basic installs and aren’t equipped with the equipment and know-how to detect where the leakage is coming from. Surprised they haven’t contacted the guy named on the letter. He should be able to schedule the proper techs to come fix the problem.
They drive through neighborhoods with signal sniffing equipment.
Years ago I got a similar notice from my non-Comcast cable company. Made an appointment to get it fixed. I had 5 way splitter feeding various devices that I had purchased from a large electronics retail chain. The technician told me it was a piece of crap, replaced it with a good splitter for free and that was that.
It always reminds me of Monty Python’s Cat Detector Van, “I never seen so many bleedin’ aerials…”
I work in a TV station and we have our own independent cable system. We have had calls from the FCC about signals emanating from our building which were picked up by the SarSat satellite on the frequency reserved for distress beacons. We have to make sure that all wiring is double shielded and unused connections are terminated with 75 ohm resistors.
I’ll add a bit more to the RF leakage info, having spent more than my share of time chasing and fixing leaks in a large metro area (DFW). Leakage can interfere with most any wireless system. This includes fire, police and ambulance radios, aircraft navigation and communication systems, over-the-air TV and radio, heck, you name it.
The FCC does indeed do flyovers of all the major metro areas and airports looking for, mapping and reporting leaks to the local CATV operators. CATV vehicles are equipped with “signal sniffers”, although these are nearly as advanced as some of the more paranoid might suspect. They are non-directional, and merely report signal strength on one or more frequencies on a meter and in some cases with an audible signal. We called them “growlers” because of their distinctive sound. If the leak was big enough, they’d howl quite loudly. They can be dismounted and connected to a dipole antenna allowing a tech to roam on foot and manually triangulate the source. CATV operators are fined if leaks reported to them by the FCC (or even customers, if they know who to call) are not repaired within a time frame (sorry, I forget if it’s 30 days, a week or whatever… been a while).
I had one customer who being both cheap and ignorant of RF propagation had wired an outlet to his daughters bedroom with twin-lead wire (you know, the type that your grand-dad had running from the antenna on the roof to the B&W TV). He really didn’t want to talk to me, a perceived “cable TV installer flunkie”, until I explained that if he wouldn’t allow me to fix the problem, I’d have no choice but to disconnect his service. I led him to my truck, where I hooked up a VIP box (some techs carry these, they decode everything) to a small TV and then plugged a cheap set of radioshack rabbit ears into the converter and we stood in the alley and watched pay-per-view for a few minutes with crystal clarity. That convinced him. I offered to run a new outlet for him for free, but he declined (I was getting kudos for fixing leaks, not doing wiring… I had no real time constraints). I hooked him up with about 100 feet of our standard coaxial cable with proper fittings and a splitter so he could rig his “free extra outlet” properly. CATV techs aren’t always lazy buffoons, eh?
The best experience I had was with an amateur radio operator. He not only knew there was a leak and how to explain it (ie. properly), he also had triangulated the leak location for me! It took me all of about 30 minutes to do the repair and he had better detection equipment than any cable company dreamt of, so when he said “It’s fixed!” you can bet I believed him.
Oh, the biggest culprit for leaks? Squirrels, or tree-rats as we called them. They’re oh-so-lucky to be cute little bastards.
#12 – You say some techs carry a box that decodes everything? You realize you’ve just inspired a whole round of vehicle break-ins and/or muggings?
More likely inspired a round of vehicle inspections and rules.
What is a good way to detect/profile leakage at home? I used to chase electric fields around with an AM radio tuned between stations. It was a great hack; a fine way to convince people to treat CRT screens with some care.
I’m sure it won’t work for such hi freqs. Anybody know a trick?
June 14, 2009
Comcast showed up unexpectedly and said leakage was occuring from my home and interferring with police/fire frequencies. It turned out that old cables from 15+ years ago were leaking transmissions. Comcast had to rewire all throughout home – moving furniture, etc. going thru walls. If I hadn’t been home, they said they would have left a note to call, and if I did not call, they would have disconnected my service.
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