Distress Signal Emitted By Flat-Screen TV 514
pinqkandi writes "CNN is a running a story on an Oregon college student's flat-screen Toshiba TV which was releasing the 121.5 MHz international distress signal. He was unaware of the issue until local police, search and rescue, and civil air patrol members showed up at his apartment's door. Apparently the signal was strong enough to be picked up by satellite and then routed to the Air Force Rescue Center in Virginia. Quite impressive - luckily Toshiba is offering him a free replacement."
I bet he was hacking Dishnetwork... (Score:5, Interesting)
What a coincidence that a college student (no money) would be doing something technical (education) to get TV for free.
EMI testing is a bitch. (Score:5, Interesting)
You have to do it if you make any kind of electronics, but it's a big burden for small manufacturers.
It'd be nice to have the choice of saying "this passes" vs "this probably passes". Current FCC/CE regs require everyone to meet the spec, and this is a bit onerous IMHO. It locks some innovative small companies out of the game.
Re:Must have been quite powerful (Score:5, Interesting)
Re:Must have been quite powerful (Score:5, Interesting)
Re:Must have been quite powerful (Score:5, Interesting)
Google cache link [216.239.39.104]
It was really funny to watch them play DVDs to test out the screen because they would always have the "this video not meant for public viewing" warning before broadcasting it out to the entire south side of Fayetteville. :)
Re:Must have been quite powerful (Score:3, Interesting)
Hardly. Hams have talked around the world on low power battery radios (although not on this frequency range). It's not that suprising that something plugged into AC power was able to get a signal to a receiver in straight line of sight, even if it was a malfunction. And the receivers are designed to pick up weak signals, there are even watches [redfingerprint.com] made that can send the emergency signal (and note that they don't have an external antenna, which at this frequency should be quite large!) Now think that a TV might be attached to an antenna of the proper size for this frequency (it's between TV channels 6 and 7 and just a little above the FM broadcast band). Which is more amazing, that a small watch can get the signal to the satellite, or a TV plugged into the wall with a full size antenna might have a signal that gets out?
Re:Fine? (Score:3, Interesting)
And, if it is a "Class A" device, the manufacturer warrants that it will not interfere in a residential environment. (Though, many electronic devices sold for residential use are "Class B", requiring the operator to take corrective action if they interfere, and letting the manufacturer off the hook. Yes, this is a simplification)
I stand by my position: the manufacturer should be liable by virtue of their likely warranty that this won't happen. Yes, even if people die, because the device is operated. (And the manufacturer should be held accountable for the resulting wrongful deaths.)
If this were not the case, the manufacturer could just "walk away" from the defective unit, leaving the purchaser with a $5k-$15k television that they can't watch -- it still performs as a TV set, after all, and isn't "defective" with regard to it's primary functionality.
What should happen is that Toshiba should immediately come to terms to compensate the owner for the inconvenience in exchange for an agreement to not operate the set until a replacement is delivered. A rational settlement would be the cost to Toshiba if they had to compensate those expected to suffer because of the continuous operation of the set. So, if there was an expected 0.1% chance of $100,000,000 wrongful death suits, Toshiba should offer $100,000 and a repaired or replaced set in exchange for an agreement to not operate the defective one.
The simple replacement of the set is, IMHO, insufficient.
Re:Must have been quite powerful (Score:5, Interesting)
Re:Error on the side of caution is great! (Score:5, Interesting)
Nick
Butte County Search & Rescue [buttesar.org]
Re:Must have been quite powerful (Score:2, Interesting)
Re:Must have been quite powerful (Score:4, Interesting)
Re:Error on the side of caution is great! (Score:5, Interesting)
On the minus side sometimes a pilot will broadcast on 121.5 becuase he thought he was trasnmitting on the other radio. (Been there, done that)
Re:The relationship of 121.5 Mhz to NTSC video (Score:3, Interesting)
Re:The relationship of 121.5 Mhz to NTSC video (Score:3, Interesting)
"This is where the problem lies. 121.5 MHz divided by 7722 is exactly the same frequency as the horizontal in an NTSC color video signal. The 7722nd harmonic shouldn't really be that strong, right?"
No, In this instance.. the TV set in question is radiating a strong Tempest radiation signal [electronic...itions.com] which happens to be at 121.5 MHz.
TV set's are for the most part,aregiant RF amps. Amplifying a video signal until it reaches the phosphors in picture tube, where some of that RF energy gets converted into visible light. All it takes is a tiny fraction(0.1%) of the TV set's overall power(120W) consumption to leak out and it can cause problems like the one described in this article.
IE. The rise/fall time of the picture tube electron gun amp(s) happen to have some component(~4.115ns) which emits a strong 121.5 MHz signal.
Re:Must have been quite powerful (Score:1, Interesting)
Comment removed (Score:5, Interesting)
Re:Must have been quite powerful (Score:5, Interesting)
One of my old friends came home to finding his home in a mess after local authorities gained entry to investigate a signal causing interference with a local airport about 3 miles from him.
The issue ended up being a problem with his cable box, which they had figured out before he even arrived.
Re:The relationship of 121.5 Mhz to NTSC video (Score:3, Interesting)
When tuning along the dial, these signals can be heard at specific intervals. The interval spacing is the fundamental frequency. Each point is a harmonic. In this case it does not "just happen" to be at 121.5 MHz ... it is at 121.5 for a reason, and that is because the 7722nd harmonic of the horizontal sweep frequency is 121.5 MHz.
Which harmonics are stronger does depend on the waveform of the involved signal. A sawtooth is going to have a fast rise and slow decay. And that fast rise time can favor those harmonics that happen to have intervals around where harmonics of a waveform which had both fast rise and fast decay with the same time interval would show up (a higher frequency and this a larger spacing).
Re:Actually (Score:5, Interesting)
> network, so it really was in a state of
> distress.
I had a TV (also by Toshiba, coincidently) that would crash when it showed the local community channel. When that happened, it did not accept any key presses on the remote or on the TV set itself, so I couldn't change the channel anymore.
Basically, my TV forced me to watch the horrible Hamburg community channel.
I complained to Toshiba and it turned out that this channel aired a non-standard Teletext that had the ability crash this particular TV's teletext decoder.
Comment removed (Score:3, Interesting)
Comment removed (Score:3, Interesting)
Dodgy TV software? (Score:3, Interesting)
My TV (a Panasonic) has a similar problem with DVB (i.e. terestrial digital tv) in the UK. It will sometimes lock-up and I have to power it off completely in order to get it to work. I presume it's either due to poor transmission error handling or bad coding when handling the interactive menus that can be broadcast with DVB.
Re:Must have been quite powerful (Score:5, Interesting)
And even more depressing that someone would choose to see the capability of receiving a distress signal as something other than a good thing (TM).
This is /. I've seen people argue in favor of getting rid of 911 because they don't think they should have to pay for something they rarely use when the injured person/person being raped/person reporting a lost child could just as easily look up the seven digit number for the local authorities. I mean gosh that E-911 charge on my last bill was like $1.49.
Nobody ever said people were logical. Politics and human nature aside I want to know how powerful of a signal this thing was putting off -- what kind of receive gain do you suppose those satellites have?
Re:TWC is not a monopoly (Score:3, Interesting)
I'm not directed this to you, so please don't take offense. But its comments like these that I hear often that basically state that cable companies are evil and greedy. I'm not saying you're saying this, but for the most part that's the kind of flak I hear about TWC.
You forgot the part about TWC employing lots of local people (installers, troubleshooters, network admins, customer service reps, salesman, etc). In my experience the Dish people don't employ anybody locally beyond the installer -- and he is a subcontractor that likely cares about nothing more then the next job because they don't pay him hourly. He doesn't care about doing a good job -- his goal is to do a fast one.
I have had a few bad experiences with TWC -- specifically they couldn't downgrade my service (I love cable but I can't justify paying for it when I'm never home) to lifeline cable (network channels only) without killing my Roadrunner service. Had something to do with signal bleed and being on the very end of the line. It took two weeks to establish during which time I had no or very poor Roadrunner service and only lifeline cable service. So I took the full service back (no analog traps on the line) and it works great. Of course I'm also back to paying $73+ a month ($34 for cable, $34 for Roadrunner, $5 for local channels) and will be paying ~$90 when my specials run out.
Despite all of those problems I would rather deal with TWC because they are local. They have a local call center with local people to talk to and local installers/troubleshooters. If I don't get eventual satisfaction I can drive to their office (4 miles away) and talk to somebody face to face. Failing that I can always file a complaint with the New York State Public Service Commission because cable companies are regulated -- you don't have that protection (in NY anyway) with the dish guys. I've never had to do that but the protection is there. Furthermore according to several friends of mine using Dish Network they have outsourced parts of their support group -- so not only will you not be talking to somebody from down the street -- you stand a good chance of talking to somebody reading to you from a sheet in New Delhi.
I'll stick with TWC and consider switching to dish when they employ several hundred of my neighbors and inject taxes, payroll and volunteer activities into the local economy.
Re:Wait a minute.. (Score:5, Interesting)
Boats can be hauled by trailters to various places, including parking lots. Somebody working on their boat in the parking lot could accidentally set off the emergency beacon. Airplanes can and do crash, although crashing near an apartment complex without being noticed might be a bit of a stretch.
At the point the signal is localized to an apartment building, its probably pretty clear that it is not an intentional distress signal (although I suppose somebody could have been kidnapped and found an emergency beacon sitting in the kidnapper's closet...). They still need to find and disable whatever is creating the signal, though, to avoid interfearing with a real distress signal in the future.
Sounds Sketchy (Score:2, Interesting)
Cool, not scary. (Score:1, Interesting)
When I want to 'bug' someone, wireless is last on the list.
1)just sidle up and listen in
2)hire someone who is a confidant of the person you want info from
3)hire someone who works for the person you want information from and is privy to it.
In industrial espionage, the easiest way to get information is to entrap a worker by paying him some seemingly large sum for some seemingly trivial bit of information. From this point on, the pay goes down and the quality of the info goes up as you've now got the stick (loss of job and reputation plus possible criminal prosecution) as well as the carrot.
Also, SOP for FBI in gathering personal information that would normaly be denied to them by privacy act(s).
Re:Must have been quite powerful (Score:3, Interesting)
TV software & HW from other commercial devices (Score:2, Interesting)
I was recently given a TV by a friend, who had upgraded hers.
I very rarely watch tv, as I find few shows are a reasonable quality. When I do watch TV, the new tv occasionally crashes. When it crashes, it simply switches off, and won't restart for long periods of time (even after unplugging for several minutes). I wonder if it's a software thing?
Are TV's really this prone to poor programming practices?
It sure would be interesting to know why the TV in the article was emitting that frequency... an extra solder bridge? Poor programming? Malfunctioning display?
I guess the picture was still fine, or the owner would have returned it earlier, right?
How many other domestic devices that are FCC compliant, with the little 'rf safe' type stickers generate stong RF like this? I've often wondered about mice and motherboards, because I have occasionally run across a computer where the speakers pick up the digital signal from the encoders in the mice. So when the mouse is moved, you can hear a clicking sound from the speakers.
Re:TWC is not a monopoly (Score:3, Interesting)
I have TWC Roadrunner only. I don't pay for cable service of any kind. And eventually TWC got tired of sending guys over to replace traps so they just took all of the damn things out and I haven't had any problems since.
My problem was that (even though I actually live in town) I was at the end of the line (dead-end street at the bottom of a hill) at the end of a 300 foot long driveway. The wiring from the pole to my house was RG8. They swapped that out with RG11 -- didn't help. Swapped out the traps -- didn't help. They finally wanted to run a separate run from the poll to my house for the Roadrunner and a separate run for the cable. They wouldn't just remove the traps and leave it at that. I vetoed the separate cable idea because it was going to take two weeks to set it up and they wouldn't promise me that it would fix the problem.
The Roadrunner service worked great without the traps -- horrible with them. It worked for over a year on subpar cable (they claim that RG8 runs shouldn't exceed 150 feet -- counting inside wiring mine was over 500 feet) -- the minute those traps went on it was worthless. Now with the traps removed it is working like it old self again -- I get the full 3.0mbit download/384k upload with zero packet loss at all times of the day. I don't notice any difference between the RG8 or RG11 cable with my Roadrunner or standard cable service. At least my landlord got a brand new cable run out of the deal for all my troubles.
The sad thing is I actually like the cable service. If I do watch TV I'm usually watching History Channel or USA (Law and Order buff). I also like South Park and Jon Stewart. But for the 10-12 hours a month that I spend watching TV it's not worth $45 -- and now I'm stuck with it because I refuse to accept subpar Roadrunner service. When my specials run out I do plan on calling them and throwing out the "S" word (satellite) to get a better deal -- they give out $20/mo retention bonuses without even asking around here -- but it's still a lot of money.
(And BTW I have no idea what is or isn't on the cable as far as TV channels are concerned. I'd rather have rock-solid Internet access than get caught finding out and have to have those damn traps put back on.)
I don't think they'd catch you -- since the advent of digital cable they don't even seem to bother doing audits around here anymore -- I know a lot of people that are billed for basic cable that have every stinking (non digital) channel because the cheap traps that TWC use failed and their own technicians removed them but neglected to return with new ones or inform billing that they were removed. They don't really have an easy way to know if you hook up an extra device (TV) and probably wouldn't bother looking anyway. Of course all that said if you don't really care about TV anyway (I don't care too much) why bother stealing the cable?
Re:Cool, not scary. (Score:3, Interesting)
In industrial espionage, the easiest way to get information is to entrap a worker by paying him some seemingly large sum for some seemingly trivial bit of information. From this point on, the pay goes down and the quality of the info goes up as you've now got the stick (loss of job and reputation plus possible criminal prosecution) as well as the carrot.
That's the way you "flip" someone with any kind of espionage not only industrial. I'm wondering where your point about possible criminal prosecution comes into play for industrial espionage? If I tell a competitor some trade secret about my employer I haven't broken any laws -- my employer can sue me and probably ruin my life but they can't put me behind bars. And unless you have some sort of NDA it's likely that all they could do is fire you.
Of course that's not to say that other laws wouldn't have been broken. If anyone ever offers me a large sum of money to sell out my employer I'll make sure they 1099 it and that I claim it on my income taxes ;)
Re:Sounds Sketchy (Score:3, Interesting)
Additionaly these are extremaly short wave-lenghts, so it would be rather easy to put a parabolic reflector 10 or even 100 wave-lengths wide on a satalite make it extreemly directional, almost optical for high gain. The wave-guides and striplines would also be physicaly small makeing it easier to put more powerfull amplifiers in the birds.
Also it's possible that a device doesn't need to store the power, external power can be beamed in via microwaves at a different frequency, adding the advantage of being able to turn the device off durring bug sweeps.
Re:Must have been quite powerful (Score:3, Interesting)
If you are looking at only one frequency, yes. However, as they've been used more, the receivers have kept up. When it was thought up by actress Hedy Lamarr, it would have been quite effective, given the tracking devices at the time, to prevent the enemy from finding a sub based on tracking the communications. However, by the time it was in full use, the receivers and trackers both advanced to where it lost this advantage. It did gain a security-through-obscurity benefit in that if you didn't know where to look next, you wouldn't be able to understand the communications, even if you could track it.
I thought the idea was that if you did spread-spectrum right it just looks like noise... isn't that why they invented it? How could anyone detect that just by sniffing?
It doesn't work like that in the real world. If you turn on and off the communications, someone will see the noise floor change. If you leave it on all the time, the noise can be tracked to you (even noise has an origin that can be tracked), but no one will see the noise floor change. So, you have to have a few dB at least above the regular noise for a good signal, so it is detectable. And even if it looks like noise, someone can track where noise is coming from, so it isn't safe.
Re:Actually (Score:1, Interesting)
You are confusing this sort of programming with regular news and anchoring, something that most networks try to seperate, but only Fox News succeeds in doing. Does anyone remember Peter Jennings remarks on the morning of 9/11? There is your bias.. straight from the news desk.