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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."
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Distress Signal Emitted By Flat-Screen TV

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  • Actually (Score:5, Funny)

    by Anonymous Coward on Monday October 18, 2004 @11:40PM (#10562149)
    It turns out it got stuck on the Lifetime network, so it really was in a state of distress.
    • Re:Actually (Score:5, Funny)

      by Anonymous Coward on Tuesday October 19, 2004 @12:11AM (#10562362)
      No, it got stuck on Fox News' channel.
    • Re:Actually (Score:5, Interesting)

      by Hanno ( 11981 ) on Tuesday October 19, 2004 @04:09AM (#10563089) Homepage
      > It turns out it got stuck on the Lifetime
      > 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.
      • Dodgy TV software? (Score:3, Interesting)

        by N Monkey ( 313423 )
        "I had a TV (also by Toshiba, coincidently) that would crash when it showed the local community channel."

        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:Actually (Score:5, Funny)

      by uncoveror ( 570620 ) on Tuesday October 19, 2004 @07:27AM (#10563785) Homepage
      Actually, all TVs have been spying on us since the V-Chip was introduced. [uncoveror.com] The real question here is what was this guy doing that set the alarm off. Maybe he was trying to disable the V-chip [uncoveror.com] without knowing how to do it correctly.
      • Re:Actually (Score:4, Funny)

        by Melantha_Bacchae ( 232402 ) on Tuesday October 19, 2004 @02:29PM (#10568345)
        Let's see, if you combine the alleged abilities of the V-Chip, the Hollings bill (to put DRM in everything - fortunately shelved), and TVs sending out SOS signals, you get....

        Chuck EyePea had just got a brand new TV and satellite system for his birthday. He couldn't wait to use it, but he wasn't going to be there for his favorite show. So he tried to set his new system up to record it...

        The door busts open, and in rush a bunch of police and paramilitary types.

        "Step away from the remote, son. Slowly."

        "But I..."

        "Save it for the judge!"

        The cop snaps up the new remote and punches a code into it. The TV proudly announces:

        "Welcome to IP Court TV! Judge John will hear your case in two minutes."

        Chuck looks like he wants to say something, but a glare from the cop silences him. Judge John comes on the screen.

        "My data shows that you were trying to violate the IP rights of a broadcaster. Please explain yourself."

        "I was just trying to timeshift a program like I always do..."

        "You filthy repeat offending pirate! Fifty years!"

        The screen went blank as the TV shut itself off. Chuck was visibly upset:

        "Hey, don't I get a lawyer? You can't just try someone in their living room!"

        "Now, son, you know PATRIOT III abolished the frivolous use of legal services by consumers. Legal services can only be used for serious corporate matters, and the corps. all outsource. If it makes you feel better, you might get out in 65 years, if you behave really well."

        "65! Whatever happened to fifty years? And parole?"

        "Chief Justice Ashcroft declared positive parole unconstitutional. Now all sentences have to be served in full, with negative parole. If you only do 65 years on a 50 year sentence, you are doing good."

        No, the above is not currently reality (that I know about). But you can bet the RIAA, MPAA, and Ashcroft have wet dreams about this stuff.

        If you don't like it, work to stop it. Now is a good time to start.

        ---
        In America, even the AntiChrist can become president.
        And currently - is.
  • by metlin ( 258108 ) * on Monday October 18, 2004 @11:40PM (#10562152) Journal

    I'd originally read this on CNet [com.com] a while ago.

    And the (CNet) article points out something of relevance - with so many new devices and what not, our radio spectrum is increasingly becoming very muddled and interference a lot more commonplace. I wonder if existing regulations would do, or if new ones be required.

    Something to think about.

    And I wonder how powerful that signal must have been to have caused such interference. Either that, or the receiving satellites must be having one hell of a resolution capability.

    The latter also provides some food for thought - if their satellite equipment is sensitive enough to find out interfering signals from a Television set, wonder what else they can (and do) eavesdrop :)

    What kind of Tempest attacks [wikipedia.org] do take place, I wonder. Satellite Van Eck Phreaking?

    ~adjusts tinfoil hat~

    • Seriously (Score:5, Funny)

      by Anonymous Coward on Monday October 18, 2004 @11:44PM (#10562176)
      You've gotta wonder what that guy was doing to that poor TV. (and whether the teletubbies were involved...)
    • by Anonymous Coward
      I wonder if existing regulations would do,...
      Yes, given that this happens fairly rarely.
      And I wonder how powerful that signal must have been to have caused such interference.
      Not very. Nothing uses the emergency frequency so the background is quiet. The transmitters are designed to run from battery power for days, and be detectable even from inside a smashed airplane, so the receivers are very sensitive.
    • by tonsofpcs ( 687961 ) <slashback AT tonsofpcs DOT com> on Tuesday October 19, 2004 @12:04AM (#10562322) Homepage Journal
      The 121.5 MHz (as well as 243 MHz) Distress call response is being phased out, and the newer 406 MHz call is becoming a more accepted (and used) standard.

      See the official NOAA Press Release (PDF) [noaa.gov] for deteals.
      • by dgatwood ( 11270 ) on Tuesday October 19, 2004 @12:12AM (#10562369) Homepage Journal
        Or the U.S. Coast Guard press release (HTML) here [equipped.com].

        Basically, that frequency was getting way too many false positives, so they're phasing it out. To quote the release, "121.5 MHz false alerts inundate search and rescue authorities. This is another major factor in influencing the decision to stop the satellite processing."

        121.5 MHz is in the middle of cable channel 14. Frankly, it's rather surprising that this doesn't happen -constantly-.

        • Comment removed (Score:5, Informative)

          by account_deleted ( 4530225 ) on Tuesday October 19, 2004 @01:01AM (#10562574)
          Comment removed based on user account deletion
          • by unitron ( 5733 ) on Tuesday October 19, 2004 @02:30AM (#10562824) Homepage Journal
            Cable Channel 14 does exist, they just aren't using it. The Minions of Satan, I mean Time-Warner Cable, in my area reshuffled the deck awhile back and quit using it as well. Cable channels 2-6 (low VHF) and 7-13 (high VHF) use the same frequencies as their over the air counterparts, but where over the air 14-83 (UHF) is in one continuous block of frequencies (around 470 to 890 MHz), cable uses frequencies for 14 and up that are used for many things other than television as far as over the air use is concerned.
      • by sirwired ( 27582 ) on Tuesday October 19, 2004 @06:02AM (#10563341)
        Even if the ELS frequency is being moved, it is still quite important to keep 121.5 clear, as that is also the standard voice aviation distress frequency. Aircraft voice radios can't tune into 406MHz.

        SirWired
        • by AB3A ( 192265 ) on Tuesday October 19, 2004 @08:07AM (#10564076) Homepage Journal
          Mod parent up.

          For those of you who might be wondering what this costs: Replacing an ELT on an aircraft is not like replacing an EPRIB on a ship. You need to ensure the shock switches fire appropriately, and that the unit is mounted such that it will survive a crash.

          The last time I explored that option for our airplane we were staring at something around $1200 to do this upgrade. It's hardly chump change.

          Further, we need to get our navigation gear coordinated so that the 406 MHz signal has GPS to feed to the world. That's not easy to do for aircraft without panel mounted GPS navigation receivers.

          Also, new regulations regarding the pointless ADIZ around Washington DC practically require pilots to monitor 121.5 to respond to an intercept if one happens. If you hear callsign "huntress" on the air and they're operating in your vicinity, remember to be on your very best behavior.
    • by rob13572468 ( 788682 ) on Tuesday October 19, 2004 @12:22AM (#10562416)
      i have talked a few times with someone who worked in the TSCM business (surveillance countermeasures). these are the real guys, not the ones you see with the $99 bug detector. the standard range that they now perform sweeps in goes from DC-300 ghz. i was naturally very interested in what they would be looking for above 30ghz and while the person i talked to admitted that he never personally found anything up in those frequencies, it was well known in their community that such devices were known to exist though they would likely be the domain of only the top government agencies. at any rate the device that he described would look something like the size of a coin and be able to send data in the high ghz range using spread spectrum burst communications directly to an overhead LEO satellite; essentially the ability to bug someone from space using areas of the spectrum that most would never look at and even if they did would likely never actually "see' the transmission unless they were lucky enough to see it transmitting and then only if they were knowledgable enough to recognize the signal from the surrounding noise. scary, huh...
    • by Smoodo ( 614153 ) on Tuesday October 19, 2004 @12:28AM (#10562437)
      I'm certainly glad that it was detected and responded to. I hope the spectrum doesn't get too messy and create this situation often, but it does show that someone is paying attention when there is a cry for help. (Thinking out in the ocean here).
      • by nick0909 ( 721613 ) on Tuesday October 19, 2004 @01:33AM (#10562680)
        I am not sure if you have ever listened to marine radio near an ocean, but just from my time near the water and listening in, the US Coast Guard has about 10 ELT (121.5MHz) distress signal activations per day, per Coast Guard Group (IE, San Diego Group, Los Angeles Group, etc). They send someone to investigate each one, eventually, and they are all nearly accidental or malicous trips, not real emergencies. It has almost reached the point of too many cries of wolf.

        Nick
        Butte County Search & Rescue [buttesar.org]
        • by Gordonjcp ( 186804 ) on Tuesday October 19, 2004 @02:20AM (#10562799) Homepage
          There was a guy in Glasgow, who lived not far from where I am now, that worked alongside one of my friends on a North Sea oilrig. He took a positioning beacon home with him (why? Who knows? It's four feet long, bright orange, and very heavy. How did he even get it about the helicopter?). He then placed his purloined "toy" in a cupboard. One of his children knocked it over, a couple of weeks later, activating it. Within 10 minutes, there was a Coastguard helicopter hovering over this house in the middle of Maryhill...
      • by Zachary Kessin ( 1372 ) <zkessin@gmail.com> on Tuesday October 19, 2004 @02:34AM (#10562835) Homepage Journal
        121.5 is very well monitored. For one thing almost any aircraft that has a radio that its not using for something else will probably have it on the guard frequency. This is a post 9/11 thing for the most part but a good one. IF you do broadcast on 121.5 every airliner up at 35,000 ft within a few hundred miles may hear you. One of them will relay your message to someone who can help you. Thats a very good thing!

        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)
    • by mercuryresearch ( 680293 ) on Tuesday October 19, 2004 @12:46AM (#10562514) Journal
      Actually, not that powerful, relatively speaking. A typical 121.5 EPIRB puts out 75-125 milliwatts. Keep in mind this is VHF and the satellites are typically NOAA birds in low-earth orbit expecting a line of sight signal, so 100 milliwatts is very workable.

      The issue with 121.5 EPIRBs is all they do is send a warble tone -- no ID, location, nothing. All the processing is done by the rest of the infrastructure, and even then the output is basically a position (still no ID) to within a mile or so -- with people using radio-direction finders narrowing it down more.

      The newer 406 MHz EPIRBs have specific user data and location information transmitted in their digital packets, so not only do they know the where, but they also know the who -- so when they get a boat beacon originating at someone's house they pretty much already know it's a false alarm.
      • Just because the alarm is put in a boat doesn't mean it has be to be activated for a boating accident.

        Why do you think they currently react to "emergencies" like this leaking tv? Because if they don't someone could die.

        Rescue services have to respond to every call even if they know it is false. Because if they guess wrong peoples life are at stake.

        They also can't just send a clerk on a moped to find out because if it is real that would loose time.

        It says a lot about politicians that in these days of cut

      • In college, I was able to talk with Cosmonauts on space station MIR on the 144 MHz amateur radio band with a 1-watt hand-held radio, and that was using FM.
    • Another writeup, from the town paper where it happened: Corvallis Gazette-Times [gazettetimes.com], and another from the Eugene Registar-Guard here [registerguard.com]. On a side note, I'm suprised they responded so quickly, less than 24 hours between recieving the signal and a response team at the door. I used to live in the area, and Corvallis is a small (pop. 50k) college town, with some hills and rivers in the area but nothing like a mountain that would require a large search & rescue squad. I guess it's good to know they're there, thoug
    • by Lord Kano ( 13027 ) on Tuesday October 19, 2004 @12:55AM (#10562549) Homepage Journal
      If the technology that they have let us know about is able to pick up a signal generated by a plasma TV, I really wonder what they're keeping under their hats.

      Most of us only half-believe the stories about echelon and massive gov't surveillance but things like this tell me that our fears may be more reasonable than we think.

      LK
    • by the_ed_dawg ( 596318 ) on Tuesday October 19, 2004 @12:58AM (#10562562) Journal
      This isn't actually the first time something like this has happened. They actually started looking for a downed plane at the University of Arkansas's Razorback Stadium in 2000 when they fired up their new scoreboard. Talk about powerful... before they finished the enclosing the stadium, you could see it clearly from the interstate coming into town -- about five miles away.

      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. :)

    • And I wonder how powerful that signal must have been to have caused such interference. Either that, or the receiving satellites must be having one hell of a resolution capability.

      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 ar

    • by Gordonjcp ( 186804 ) on Tuesday October 19, 2004 @02:27AM (#10562813) Homepage
      Probably not very strong. You can get ELTs built into a *watch* - not even a very chunky watch either. They are about as big as a decent diver's or "marine" watch, with a slightly fat cylinder worked into one edge (not exactly bulky). You unscrew the cap and pull out a wire aerial, which activates the transmitter. The wire is resonant (making it about 18" long) but it just dangles loosely. It runs for a couple of hours off a pair of watch batteries, so the signal must be in the order of tens of milliwatts. Even though the signal is pulsed, there is a limit to the maximum current you can draw from these tiny batteries.


      The signals are received by three satellites, to triangulate the position of the transmitter. I don't know what kind of antenna the receiver uses. Bloody big ones, I would think.

  • by RC_Car ( 778076 ) on Monday October 18, 2004 @11:43PM (#10562167)
    "So if you need to transmit an international distress signal then stop by any local store and turn on a Toshiba flat-screen TV. We should be able to locate you in a matter of minutes."
  • by Anonymous Coward on Monday October 18, 2004 @11:43PM (#10562168)
    You can relax now. The aliens aren't coming just yet.
  • I bet . . . (Score:5, Funny)

    by Mod Point Sink ( 811047 ) on Monday October 18, 2004 @11:43PM (#10562171)
    . . . this is the last time that guy is a smartass to the salesman at Best Buy when buying a TV, though!
  • by Dancin_Santa ( 265275 ) <DancinSanta@gmail.com> on Monday October 18, 2004 @11:43PM (#10562172) Journal
    The TV probably gained sentience and realized the crap that was being fed to it. It responded in the only way it knew how.
  • by BongoBen ( 776302 ) on Monday October 18, 2004 @11:43PM (#10562173)
    Yeah, this gives me an idea for a new TV feature. Whenever you lose the remote control, it sends out a destress signal until a search team shows up to find it. Now that's service!
  • Shrug (Score:5, Funny)

    by ciurana ( 2603 ) on Monday October 18, 2004 @11:43PM (#10562174) Homepage Journal
    "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."

    Big deal. Now, if that had been a free, unencrypted feed of the Spice or Playboy channels...

    Cheers!

    E
  • by Flounder ( 42112 ) * on Monday October 18, 2004 @11:44PM (#10562181)
    Warning!
    This television will send out a distress signal to authorities whenever any program catering to an IQ of less than 80 is viewed. This includes games shows (Jeopardy excluded), reality shows, Spongebob Squarepants, and the CBS Evening News with Dan Rather.
  • Yeah.. (Score:4, Funny)

    by LewsTherinKinslayer ( 817418 ) <lewstherinkinslayer@gmail.com> on Monday October 18, 2004 @11:44PM (#10562184) Homepage
    I had a similar problem with my toaster emitting moorse code signals.
  • It's well known that certain hardware hacks [google.ca] for Dishnetwork receivers emit this same frequency.

    What a coincidence that a college student (no money) would be doing something technical (education) to get TV for free.
  • by ferrellcat ( 691126 ) on Monday October 18, 2004 @11:46PM (#10562201)
    "Please Help! My plasma is burning out! I'll need to be replaced in 2 years!"

  • by seanadams.com ( 463190 ) * on Monday October 18, 2004 @11:47PM (#10562208) Homepage
    We just spent $10K+ on in-house EMI equipment, to mitigate the costs of having an outside lab help with troubleshooting.

    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.
    • Great idea! (Score:5, Funny)

      by Raul654 ( 453029 ) on Monday October 18, 2004 @11:57PM (#10562270) Homepage
      So we are supposed to trust companies to use their judgement and ethics when slaping a "This device probably meets federal EMI regulations" sticker on a device. I feel better already.
    • by metlin ( 258108 ) * on Tuesday October 19, 2004 @12:02AM (#10562304) Journal
      The problem is that while in your particular instance it may seem stiffling to your company, those regulations are in place because not all companies can be trusted to stick with the specs in that case.

      It becomes a question of business ethics, and we all know how most companies are when it comes to those. This device probably passes the test, where probably has a probability of 0.00001.

      _That_ is why strict regulations are needed, IMHO.

      And oh btw, nice players at Slim Devices, quite the coolness.
  • Signals (Score:5, Informative)

    by Anonymous Coward on Monday October 18, 2004 @11:48PM (#10562218)
    For those who are wondering what type of signal this is, check here:

    http://www.navcen.uscg.gov/marcomms/gmdss/epirb.ht m [uscg.gov]

    Animah S/V Solaris

  • by amigoro ( 761348 ) on Monday October 18, 2004 @11:51PM (#10562236) Homepage Journal
    There's another digital distress signal [amsa.gov.au] too. The 406 MHz distress beacon emits both an analogue 121.5 MHz signal and a digital 406 MHz signal. The digital signal carries a code which identifies the beacon while the analogue signal is to enable aircraft to home on location. That digital code can be cross referenced with a database of registered 406 MHz beacon owners held at AMSA which identifies who is in trouble and what type of situation they are in. This enables the search and rescue authorities to tailor a response to the emergency situation.

    Moderate this comment
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  • by Zorilla ( 791636 ) on Monday October 18, 2004 @11:52PM (#10562238)
    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...

    In other news, a man's 4-door sedan was emitting the 1.21 jigawatts necessary to power the flux capacitor. Christopher Lloyd was unavailible for comment.
  • A better writeup (Score:5, Informative)

    by RotJ ( 771744 ) on Monday October 18, 2004 @11:53PM (#10562249) Journal
    Corvallis Gazette-Times [gtconnect.com] has more details and a picture of the guy posing with his TV. Apparently, he mostly watches public broadcasting and has acquired a taste for all the quality children's programming it provides, especially "Arthur".
  • by ets960 ( 759094 ) on Monday October 18, 2004 @11:58PM (#10562282) Homepage
    It scares me that it took them almost a year to get the distress signal. Remind me never to get lost at sea.
  • Of course! (Score:3, Funny)

    by Flexagon ( 740643 ) on Tuesday October 19, 2004 @12:02AM (#10562306)

    He was probably watching an ad with an image of new currency, and the TV detected the anti-counterfeit pattern [slashdot.org]. :-)

  • Can you really blame the TV for sending out an SOS? Be fair to it.
  • Signal Details (Score:3, Informative)

    by blystovski ( 525004 ) on Tuesday October 19, 2004 @12:11AM (#10562356) Homepage
    I, too, was wondering about the specifics of this "international distress signal". Getting lucky (google) with "121.5 Mhz" gives the following link which specifies a relatively simple AM signal with less than 100 mW radiated power! That's not much these days, and I'm rather shocked (har har) that it's taken this long for a device to accidentally trigger such a search. Anyway...here's the URL...

    http://www.cospas-sarsat.org/Beacons/121Bcns.htm
    • Re:Signal Details (Score:5, Informative)

      by flyboy974 ( 624054 ) on Tuesday October 19, 2004 @12:27AM (#10562434)
      You'll be waiting ~ 3-4 hours before somebody comes and finds you, if they are really good at it.

      First, wait for a satellite pass will notify the Air Force. They will then verify it if they can, contact the FAA for missing flights, etc. The next call goes out to the Civil Air Patrol wing that is responsible for that area. They in turn will normally notify the local authorities who are in charge of S&R. Of course, when you broadcast on 121.5, that sound is audible in every Airtraffic Control center that it can reach.

      Once they have done this, they will organize a ground based S&R party and try get a general area of where the signal is coming from. Remember, this is non-directional, so they have to go to a few different places, measure the direction and approx. strength of the signal, and then they will know about where it is. Triangulation sucks, esp. with trees and mountains.

      Once they have done this, they'll start their search. Oh, if it's at night and it's not somewhere near them, they'll wait until the morning. Hope you don't keel over at night.

      Finally, once they triangulate it, they home in on it. In this case, they homed it to an apartment. Questioned the guy, and went back out into the hallway and confirmed it was coming from there.

      So, do you REALLY want a 121.5 ELT locator? I would get one of the new 406mhz ones which are digitally encoded with your information. In addition, some models offer GPS in them that will transmit your GPS coordinates when it sends it. Much nicer and easier to find.

      Oh, and I'm not a CAP member any more. But, it was fun while I did it. Not enough time now, but, maybe after I'm done building my airplane I'll have time.
      • Re:Signal Details (Score:4, Informative)

        by nick0909 ( 721613 ) on Tuesday October 19, 2004 @01:54AM (#10562734)
        I also recomend the new 406MHz PLB's, but PLEASE PLEASE get one with a *good* GPS built in. The 406MHz PLB has to go through the same doppler-shift tracking as the 121.5 ELT's if there is no GPS data with the signal, and the AFRCC will wait until that narrowed-down data has come in before notifying the agency having authority.

        And most the time we don't wait until daybreak, we like the challenge ;)
        Nick
        Butte County Search & Rescue [buttesar.org]
  • by rune2 ( 547599 ) on Tuesday October 19, 2004 @12:12AM (#10562367) Homepage
    Your tinfoil hats
  • by EvilStein ( 414640 ) <spamNO@SPAMpbp.net> on Tuesday October 19, 2004 @12:38AM (#10562483)
    TV:"Oh, please God.. I can't take another episode of "Survivor" and I'm so sick of "The Surreal Life" these days.. help me!"

  • by russint ( 793669 ) on Tuesday October 19, 2004 @12:48AM (#10562524) Homepage
    On October 2, the 20 year-old college student was visited at his apartment in the small university town by a contingent of local police, civil air patrol and search and rescue personnel.
    [...]
    Authorities had expected to find a boat or small plane with a malfunctioning transponder, the usual culprit in such incidents, emitting the 121.5 MHz frequency of the distress signal used internationally.


    Why did they expect to find a boat/plane in a apartment building?
    • Re:Wait a minute.. (Score:5, Interesting)

      by SagSaw ( 219314 ) <.slashdot. .at. .mmoss.org.> on Tuesday October 19, 2004 @06:57AM (#10563604)
      Why did they expect to find a boat/plane in a apartment building?

      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.
  • by pizza_milkshake ( 580452 ) on Tuesday October 19, 2004 @12:55AM (#10562554)
    Langley: Forgive me, FCC, but I am receiving numerous distress signals.
    FCC : I don't doubt it.
  • by Mr. Majordomo ( 260742 ) on Tuesday October 19, 2004 @01:04AM (#10562585)
    Here's the followup traffic from a Civil Air Patrol mission in California about 10 years ago, where the errant signal was traced to a self-serve hot pizza machine (a freezer full of pizza, a microwave oven, a chute to move frozen pizzas from the freezer to the oven, and a coin/cash machine to collect the money).
    ROUTINE
    072338Z MAY 93
    HEADQUARTERS CALIFORNIA WING/MCO [NAME DELETED]
    HEADQUARTERS ALL UNITS CALIFORNIA WING
    INFO CC DO CALO
    BT
    ATTENTION EMERGENCY SERVICES PERSONNEL
    SEARCH MISSION 93XM0956 OPENED 6 MAY AND CLOSED 7 MAY FOR A
    SIGNAL INTERFERENCE ON 121.5. SIGNAL LOCATED AND SECURED IN
    A HOT PIZZA MACHINE IN NORTH PALM SPRINGS. THANKS TO MAJOR
    [NAME DELETED], FIRST LIEUTENANT [NAME DELETED] AND SECOND LIEUTENANT
    [NAME DELETED] OF
    SQUADRON 11 FOR THEIR ASSISTANCE ON THIS MISSION.
    BT
    P.S. NO FREE PIZZA.
    END OF MESSAGE
  • by carambola5 ( 456983 ) on Tuesday October 19, 2004 @01:09AM (#10562603) Homepage
    What I wanna know is how a college student has a plasma TV. Aren't college kids supposed to be poor? Whatever happened to the trusty 13"er with bad reception?
  • by Doc Ruby ( 173196 ) on Tuesday October 19, 2004 @01:10AM (#10562609) Homepage Journal
    It turns out that those government satellites are monitoring our TVs. Luckily, Toshiba sells tinfoil hats for closeup viewing.
  • by Skapare ( 16644 ) on Tuesday October 19, 2004 @02:27AM (#10562815) Homepage

    The frequency of the NTSC color subcarrier (the TV color system used in analog video standards in North America and Japan) is defined as exactly 5 MHz times 63/88. That works out to 3.579545454.... (infinitely repeating 54's) MHz. The horizontal scanning frequency is then defined as a 2/455 times the color subcarrier frequency. That works out to 15734.26573426.... (infinitely repeating 573426's) Hz (very nearly the original monochrome horizontal frequency of 15750 Hz). 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? Usually not. But the harmonics can get to be very strong overall even at such high orders when dealing with modulating the high voltages needed for the horizontal sweep. There should be some low pass filters that prevent that from getting into the VHF range. But if the filters are absent, or were incorrectly installed, or were damaged somehow, and if some wires formed some resonance near 121.5 MHz (like wires going out to cable, speakers, etc) ... a wavelength of about 2.47 meters or 8.1 feet ... it is possible that harmonic, and a bunch of others near it, could be enhanced and radiated.

    The local oscillator in the tuner is a remote possibility. But it would have to be tuned to be receiving a video carrier at 75.75 MHz based on the common satndard of 45.75 MHz for the IF stage in the tuner. But there is no TV broadcast on that frequency in the US ... though I could not rule out there being something on that frequency from a cable system. Still, it wouldn't be an expected place for a TV to tune to. But if the TV has a non-standard IF frequency, the local oscillator getting on 121.5 MHz by some expected channel could be possible. Those leak a lot and it's how the snoops can tell what channel you are tuned to by spying on the RF emitted from your house.

    If just this one TV had the problem, then apparently it must be a manufacturing defect or shipping damage (or maybe user damage or tampering). If it were a design problem, I'd sure we'd hear more about it. That probably rules out the CPU clock frequency.

    • You're only "modulating" at most a few hundred volts for horizontal sweep. It's probably the 30 or so kV for the CRT that comes from the flyback driven by the sweep B+ that had the harmonic and after a year one of the filtering components went wonky.
    • "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 visib

      • 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 th

  • by klang ( 27062 ) on Tuesday October 19, 2004 @02:58AM (#10562913)
    ..because he thought that the RIAA had finally caught up with him...
  • 132.7 MHz (Score:3, Funny)

    by ArnIIe ( 814978 ) on Tuesday October 19, 2004 @03:33AM (#10563010)
    I might buy a toshiba flat screen tv in the hope that it releases a 132.7 MHz international playboy signal !
  • by VernonNemitz ( 581327 ) on Tuesday October 19, 2004 @08:54AM (#10564490) Journal
    Obviously the TV thought it had been stolen. Did the cops check for that?
  • by Shoten ( 260439 ) on Tuesday October 19, 2004 @09:21AM (#10564741)
    Hm. If only Mr. Howell had been a gadget freak, perhaps they all would have been rescued...

There's no sense in being precise when you don't even know what you're talking about. -- John von Neumann

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