I’m sure I relayed this story here before, but while working as a dialup tech support agent I once went through a lengthy set of diagnostics and attempted fixes with a customer only to have the customer volunteer to turn off her electric fence to see if that was the issue. It was.
I heard a possibly apocryphal tale of a housing developer back when garage remotes first came on the scene who decided this was a must-have feature and had them installed on all the new houses in his development. Then they discovered they were all on the same frequency. One click and every door near you would respond!
Most of those I’ve seen will use the same frequency but transmit a different code. Our old opener at my parents’ place used DIP switches to set the code, so if they had a system like that and all set them the same it would operate as you describe. Or it could be a completely different system.
I do know that there were issues with door openers near various military bases - the door manufacturers used spectrum within the military allocations that they weren’t authorized for and when the military started using those frequencies, everyone’s doors in nearby subdivisions would stop working.
This was before codes, and I have seen a very old unit that just had a jumper to choose one of three frequencies, entirely analog!
Like Mr. Miyagi said in Karate Kid II, village small price to pay for new TV. And for honor.
Also reminds me of this incident involving an old dog bed causing interference for a radio telescope situated miles away:
One morning several years ago, Sizemore got a call. Broadband interference – noise, in common parlance – was wreaking havoc with the sensitive equipment at command central. After loading up his truck with a receiver, amp, spectrum analyzer, and directional antenna, he thundered into the countryside. Every quarter mile or so, he stopped, whipped out the antenna, and scanned the electromagnetic spectrum for spikes of activity. He methodically triangulated his way to this spot, where an elderly couple live with a nasty old dog penned in back. The couple had given the mutt a heating pad to lie on, but the pad had become worn; cracks in the wiring were causing tiny electric arcs to leap across the gaps. “Not enough electricity to shock the dog,” Sizemore explains, but enough to produce a radio-frequency signal. He promptly disposed of the heating pad and bought the couple a new one. Just one more small step in humankind’s exploration of the cosmos.
The story I read said it was a plasma screen.
It’s not that hard to make something that screams noise at this or that radio frequency, or indeed many at the same time. (Though not all of them, unless you have infinite energy to pour into it.)
But faults like this tend to be the result of extremely idiosyncratic vulnerabilities in systems that are already bathed in a certain degree of radio noise. If that TV were in a different place in the house, maybe none of this would ever have happened. Or it’s possible that whatever doohickey this was futzing with was itself faulty, such that this could be a problem in the first place.
Also, the inverse square law favors the defenders. You can always ramp that up, with a good old-fashioned EMP, but at that point you’re out of the range of sneaky sabotage and into something more like a direct military assault.
Yes, that seems like a good possibility. But it assumes a crt set, is it specified or are we seeing the photo here and assuming?
I know people have tracked down odd interference to radio that was caused by bad electric fences, or arcing with high voltage wires.
What is more a mystery is how the interference is getting into the cable system. Those have to be tight so nothing leaks put to cause interference, and a result is it’s harder for interference to get into the system.
A backhoe is the preferred tool for this sort of thing.
Yeah the 27Mhz system for the side gate in my apartment block is like that, but the switches are set to something like 000000111111. Its no more guessable than any other code, but more likely to be found by accident I would think.
This situation amuses me because as a shortwave radio listener (probably one of maybe a few dozen in the US who knows to be honest when you don’t throw in HAM radio operators) is that RFI is a common problem in that part of the radio frequency. My suspicion is that it’s a matter of how much power the older TV sets could consume to emit such a signal not so much the frequencies they interfered on. But there are some cases of low power high frequency devices like your small power brick for your phone or larger power brick for your laptop that could induce similar RFI. Especially when you consider that all power lines are effectively antennas (ground lines aren’t guaranteed to be clean if any faulty device is grounded it’ll surely send current down it).
I would argue that this is a good argument for fibre to the premises, rather than distributing your data with twisted pair cables. With copper, electrical interference can go both ways.
That would make sense. Those things can generate a very wide-band noise, so if that was getting into a cable or DSL line that could cause issues. I’m not sure which access technology the village is served by, so I can’t comment too much on that, but I know from experience that a noisy plasma TV can render pretty much the whole of the HF spectrum unusable to us radio enthusiasts (i.e. hams and shortwave listeners).
Something must have changed, though, 18 months ago for the issue to have started manifesting then. Presumably the TV set is older that 18 months, and hasn’t changed noticeably in the way it operates. I wonder if the telco (BT?) changed or moved their breakout box at that time - moving it along the street, for whatever reason - so that it was inside the area-of-effect of the TV, or if they installed new equipment and the new stuff wasn’t as robust against interference as the previous model.
If either - or both - of those occurred, then taking 18-months to track down the cause makes more sense. If you change something, and the system fails, it’s natural, reasonable, and good practice to assume that the change is what caused the failure and to work to undo the change or mitigate it. Assuming you’ve moved into an EW-attack range wouldn’t be top of mind for most fault finding checklists
The story I read said it was a plasma screen.
Oh, ok. Cancel everything I wrote I figured it must have been an old (CRT?!) TV. Assumptions! Ha!
The BBC article doesn’t specify the nature of the connection; but says that it was openreach engineers doing the troubleshooting; and it looks like they deal in either fiber or telco-flavored copper.
Unless they are using astoundingly poorly shielded fiber network gear(I’m not going to say it’s impossible; because pennies get pinched and RF is witchcraft; but it’s definitely not my first guess); it seems likely that the interference is hitting DSL; which is probably the worst-case scenario: balanced twisted pairs were pretty hot noise resistance back when telephones were taking over from telegraphs; but specifications for POTS wiring are pretty loose by most standards and DSL is all about DSP-ing your way to results that rub up against the limits of possibility for wiring of that spec.
I imagine that cable has its own ways for terrible things to happen with TV-produced interference since the odds are higher that the TV is injecting noise directly into the coax; but coax itself is much more defensively designed vs. random outside RF, optical fibers don’t even care; and while wireless options obviously care deeply about RF interference they also benefit from a great deal of design work aimed at resisting interference; since it’s an absolute inevitability rather than something that good cable maintenance might be able to mitigate.
I’m guessing it was some DSL customers; quite likely in a village that wasn’t the number 1 priority for openreach.
The TV was found to be emitting a single high-level impulse noise (SHINE)
No, that’s actually a SHIN.
an article with slightly more technical details
As UK telco Zen helpfully explains, SHINE and its relative REIN (Repetitive Electrical Impulse Noise) generate interference “in the frequencies used by the ADSL Broadband service.”
“SHINE is where this interference is generated as a burst – when a device is powered on or off, for example,” says Zen. “As a result disconnections or line errors may result at the time a device is switched on or off.”
Zen explains that an AM radio can detect SHINE-emitting kit.