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Who Needs a Satellite Dish When You Have a Wok? 250

Posted by samzenpus
from the sweet-and-sour-channel dept.
An anonymous reader writes "Why pay $20,000 for a commercial link to run your television station when a $10 kitchen wok from the Warehouse is just as effective? This is exactly how North Otago's newest television station 45 South is transmitting its signal from its studio to the top of Cape Wanbrow, in a bid to keep costs down."
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Who Needs a Satellite Dish When You Have a Wok?

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  • Focus (Score:3, Interesting)

    by rossdee (243626) * on Thursday March 01, 2007 @06:33AM (#18192274)
    Is a wok parabolic in cross section or is it circular?
    • by julesh (229690)
      The traditional design is, I believe, a spherical section. Obviously there are a variety of different wok designs, and some may well be parabolic.
    • by Anonymous Coward on Thursday March 01, 2007 @07:37AM (#18192532)
      The reflector does a couple of thing. The most obvious is that it catches the signal and focuses it on the antenna. The bigger the dish and the closer it is to a parabola, the more signal to the antenna. The other thing it does is to shield the antenna from noise. The antenna in the article seemed to be nested right inside the wok. So, the wok probably improves the signal to noise ratio (SNR) by at least double and maybe by a factor of three or four (or more if it's done right). That's very important. If your signal to noise ratio is good enough, you can use amplification to get the signal you need. If the SNR isn't good enough, then almost nothing helps.

      The wok will give a useful increase in signal strength but a more significant improvement in signal to noise ratio.
    • by DrYak (748999) on Thursday March 01, 2007 @11:15AM (#18194248) Homepage
      Yes, woks can be good enough approximations of parabolic cross section.
      And in fact, because of the wave-leght of TV, WiFi, Bluetooth, etc.. (signals in the GHz range have centimetric wave-lengths) their corresponding colanders too [orcon.net.nz] can be used as cheap antennas, and have the aditionnal benefit of having holes (they are basically metallic mesh) and therefore having less friction against winds (and lower risk of being blown away during a storm). /. have featured a few time ago an article about using wok colanders as dishes for Wifi USB dongles, and a several techniques to check is the parabolic approximation is good enough.
      - one technique, which can be done in the shop before buying the colander, is to use a small chain whose shape when suspended at both end and check if shapes match (checking if the shape is "catenary")
      - another is to cover the colander in aluminium foil and checking if a parallel light source (the sun) converge to one single point (where the USB dongle should go once everything assembled)

      See /. article " 4km WiFi Range w/ $5 DIY Antenna [slashdot.org]". TFA is mostly the same idea but applied to a different signal in the same GHz range (microwaves).
  • by tttonyyy (726776) on Thursday March 01, 2007 @06:35AM (#18192280) Homepage Journal
    More to the point, why pay to watch "45 South" when I can, more cheaply, scoop my eyeballs out with a rusty spoon from Honest Al's Hardware store.
    • Re: (Score:3, Funny)

      by asliarun (636603)
      Look at the bright side... this will help you wok from home much more effectively.
  • by Anonymous Coward on Thursday March 01, 2007 @06:38AM (#18192288)
    Can you somehow add a ball point pen and chewing gum into making the dish?

    MacGyver would just love that!
    • Re: (Score:3, Interesting)

      by mpe (36238)
      Can you somehow add a ball point pen and chewing gum into making the dish?

      Ironically last night on Discovery was a programme which explained how Aldrin had to fix a broken switch in the LEM using a pen whilst Armstrong flew the craft.
    • by Eudial (590661) on Thursday March 01, 2007 @10:21AM (#18193582)

      Can you somehow add a ball point pen and chewing gum into making the dish?


      No, that's how you make a death ray.

      Wok, ball point pen, chewing gum... yeah, that's a death ray.
      Wok, a froze chicken and duct tape, that's a satellite dish.
  • by freedom_india (780002) on Thursday March 01, 2007 @06:39AM (#18192296) Homepage Journal
    If the wok thing becomes more popular here, one or many of the following is bound to happen:
    1. Prices of Wok will increase NOT due to increase in demand, but because sellers now think it serves a dual purpose.
    2. FCC will jump in the bandwagon and demand wok makers put a minute dent to make sure it does not serve as a dish.
    3. Homeland Security will jump on the FCC bandwagon and demand that woks be classifed as potentially "interesting" and "dangerous" weapons.
    4. Carlyle Group will do a LBO against the largest Wok maker...Cheney will be richer.
    5. Canada will impose a "musician's duty" on Woks since woks can be used to transmit pirated music...

    that's all i can think of now.
  • Oblig. (Score:4, Funny)

    by cosmocain (1060326) on Thursday March 01, 2007 @06:41AM (#18192302)
    ...and now the image quality is more like...err...sweet and sour? or: what about the signal being chopped? (that one takes a second more) duh.
  • by thetroll123 (744259) on Thursday March 01, 2007 @06:41AM (#18192310)
    You can't use a $20,000 commercial link to whip up a tasty and healthy stir-fry. There's a lot of value in that $10 wok.
  • From TFA

    The classic case of Kiwi ingenuity has made its way onto the internet and the technique has been posted by an American website, Mr Jones said.
    "People wanted to know all the details about how to make their own, so it is now all publicly documented," he said.
    Can anybody provide a link to the 'American website' - he can't mean /. because TFA was posted before the /. posting.
  • Numbers (Score:2, Funny)

    by problemchild (143094)
    Yep the 10$ wok replaced 80$ of antenna which I presume is NZ dollars which is £0.35 or $0.70 a pop so you have spent all day frigging with a second rate solution to save £20 ish which I don't think realy floats evn in in NZ. The other think is that this is going via computer to computer so it's most likely a 2.4GHz WIFI + Canntenna mission which I hoped had been done to death. Even I've done 3Km between my car with a router and a Coffee can and a USB stick strapped to a mates Van Window. Old h
    • by Bob54321 (911744)
      Um not $80, it replaced a $20,000 dish. Just like is say in the summary. I can understand not RTFA but not RTFS...
      • No, it's $80 (Score:4, Insightful)

        by a16 (783096) on Thursday March 01, 2007 @08:12AM (#18192664)
        The summary doesn't say it replaced a $20,000 dish, it says it replaced a $20,000 link. I imagine the 20k number is from asking a networking company to come install a link between Site A and Site B, ie. they would have setup everything, including the systems involved etc, not just the dish.

        From TFA:

        He discovered satellite dishes were between $100 to $400 retail and that smaller dishes, the same size as a wok, were $80. Mr Jones thought he could do better. Along with friend Murray Bobbette they worked out mathematical equations to prove the curved metal face of a wok would have the same effect as a small satellite dish.

        So basically they've grown their own wireless solution, using woks. However, instead of spending ages working out mathematical equations and using trial and error, they could have bought the $80 dish and be done with it. Hence the grandparent post's point stands. Saving $20k by spending a few days developing a wireless solution is cool, but for a real world application, saving $60 on that wireless system to use a wok instead of a dish that will likely have years of development behind it is fairly silly. Like someone else has said, what about when the wok starts to rust?

        Maybe if you're going to point the finger at people for not reading TFA, you should read TFA.
        • by Dekortage (697532)

          FTA:

          When the television station 45 South (UHF channel 41) started up in September last year, Mr Jones thought the same technique could be applied. "The $20,000 for a commercial link was just money we didn't have, so we bought several woks from The Warehouse instead which was convenient and cheap," he said.

          In other words, the work they did replacing the $80 link for wireless networking was then applied to the $20,000 commercial link for television. Sure sounds like they saved more than $60...

  • The Easy Part (Score:4, Interesting)

    by Detritus (11846) on Thursday March 01, 2007 @06:54AM (#18192350) Homepage
    The dish is the easy part. I'd like to know what he used for the feed assembly.

    In the past, people have also used those circular snow sleds as the basis for building a dish antenna.

    • by Svartalf (2997)
      USB Dongle with it's tip (antenna area) placed at the right depth within the wok...
  • by ForestGrump (644805) on Thursday March 01, 2007 @06:54AM (#18192352) Homepage Journal
    Else the wok rusts out and they're off the air!
    • by ajs318 (655362) <sd_resp2.earthshod@co@uk> on Thursday March 01, 2007 @07:39AM (#18192544)
      The non-stick coating (so good, it won't even stick to the pan) would do the rust-protection thing. Although, you can get away with a few pinholes in a dish ..... just as a speck of dirt on a lens won't block out as much of the image as you might expect. Sky TV dishes are perforated to save weight and minimise wind effects.

      Re your sig: Everyone in Britain (and France, too) learns to drive in a manual car.
      • Re your sig: Everyone in Britain (and France, too) learns to drive in a manual car.

        AIUI, No, you can learn to drive and pass your test in an automatic car, but then you're not licensed to drive a manual-gear-box vehicle.
        • AIUI, No, you can learn to drive and pass your test in an automatic car, but then you're not licensed to drive a manual-gear-box vehicle.
          while the gp was exagerating slightly by saying everyone learing to drive on an auto here is damn rare because as you say taking your test on an automatic gearbox means you can only drive vehircles with automatic gearboxes. Given that automatic gearboxes are by far the exception here and are generally belived to be less fuel efficiant thats a pretty nasty restriction to li
      • Re your sig: Everyone in Britain (and France, too) learns to drive in a manual car.

        Actually not everyone learns to drive in a manual transmission car in the UK, you do have the option of learning in an automatic only car and taking your test using an automatic, BUT the license granted is an automatic transmission only license and does not allow one to drive a manual transmission, so very few people take a test that limits what cars they can legally drive.

        However, I am not sure where the dividing line is for the new wave of semi-automatic transmissions.

        • However, I am not sure where the dividing line is for the new wave of semi-automatic transmissions.

          I would expect them to be classified as automatic as a semi-automatic is just a different implementation below the interface.

      • by Dolohov (114209)
        Most woks don't have non-stick coatings, particularly not the $10 ones (which also happen to be the best ones you can buy). Most such coatings can't take the temperatures woks are usually exposed to. As such, though, rust is a big problem with them, and they have to be maintained pretty scrupulously in the kitchen.
        • by ajs318 (655362)
          If there's no non-stick, you have to make your own in the traditional way: by adding just a few ml. of cooking oil, heating the wok till the oil begins to smoulder and then wiping it around with a (thickly-folded, so you don't burn your fingers) paper towel. The partly-oxidised oil forms some sort of chemical bond with the hot metal. You have to do this every time you cook in the wok, until it's black.

          In the UK, non-stick cookware (made to last a couple of years) is generally cheaper than non-non-s
          • by Alchemar (720449)
            or you could just put a penny in a jar every day, and buy a new one ever three years.
          • by Dolohov (114209)
            That works fine for the stovetop, but I'm not keen on trying to do the outside of the wok as well, for use as a parabolic receiver ;)

            In many stores here the non-stick stuff is also less expensive (for the same reasons), but if you've got a Chinatown nearby you can frequently find a good cast-iron wok for dirt cheap.
            • "if you've got a Chinatown nearby you can frequently find a good cast-iron wok for dirt cheap."
              Just don't drop it.

              I use a steel wok. love the thing.
              -nB
  • by AceJohnny (253840) <jlargentaye@@@gmail...com> on Thursday March 01, 2007 @07:18AM (#18192456) Journal
    I want to hire the guy who thought about this and implemented it. Well, I wish...

    I work at a Big Company, where over-engineering, paying 10k where 1k would do, and endless discussion on the color of the bikeshed happen thrice before lunch every day.

    I became an engineer because of McGuyver... how disappointed I am with reality :)
    • by 16384 (21672) on Thursday March 01, 2007 @07:34AM (#18192508)

      I work at a Big Company, where over-engineering, paying 10k where 1k would do, and endless discussion on the color of the bikeshed happen thrice before lunch every day.
      Could the bikeshed be in cornflower blue?
      • If you're going to go cornflower... why not periwinkle instead? Cornflower was discontinue by crayola back in the 80s.
    • by xs650 (741277)
      "I work at a Big Company, where over-engineering, paying 10k where 1k would do, and endless discussion on the color of the bikeshed happen thrice before lunch every day."

      "Over engineering" is much misused phrase. If it's overly complicated or overly expensive for what it does, it's under engineered. Over kludged or over bought, but under engineered.
  • TV by wok, eh?
    Reminds me of the tasty and very useful Pringles antenna [google.com].

    Geeks and their obsession with food...
    What's next? A pizza box server? (no wait... scratch that)
  • by Milton Waddams (739213) on Thursday March 01, 2007 @07:31AM (#18192502)
    ...I want to cook up some chicken stir fry and watch telly at the same time?
  • Silly article: (Score:5, Insightful)

    by Ancient_Hacker (751168) on Thursday March 01, 2007 @07:42AM (#18192550)
    Rather silly article:
    • A dish, for best effect, had better be parabolic. Most Woks are not.
    • The $20K cost includes not only the $50 dish, but the feed horn, the Gallium-Arsenide MOSFET low-noise amplifier, downconverter, mount, and warranty.
    • You have to compare the downside-- if the Wok setup goes down for any reason, what is the cost per hour to the station? Initial purchase price isnt a very good barometer here.

    And this is not exactly new, mack in the 1970's we used to use $7 snow sleds to pirate HBO.

  • Late '80's C-Band (Score:4, Interesting)

    by rohar (253766) * <bob.rohatensky@sasktel.net> on Thursday March 01, 2007 @07:42AM (#18192554) Homepage Journal
    I used to install C band residential satellite dishes and we used a radar detector mounted in the front of a wok to measure microwave interference from ground towers when evaluating customer installation locatations.
  • by Two9A (866100) on Thursday March 01, 2007 @07:52AM (#18192590) Homepage
    I've got a wireless link (11g) set up between two Linksys routers. At one end, I've put a spider skimmer behind the antenna; it's one of those Chinese cooking tools used to pick items out of a deep fryer. Near-perfect parabola, wire mesh of 6-8mm, bamboo handle; ideal reflective surface for a 2.4GHz signal.

    I get about +12dB gain with the "dish" installed; not bad for £5.
    • by frdmfghtr (603968)

      I've got a wireless link (11g) set up between two Linksys routers. At one end, I've put a spider skimmer behind the antenna; it's one of those Chinese cooking tools used to pick items out of a deep fryer. Near-perfect parabola, wire mesh of 6-8mm, bamboo handle; ideal reflective surface for a 2.4GHz signal.

      Maybe all these implements were originally designed as antenna components, then one day somebody noticed that you can use a wok to make a good stir-fry...

  • Who Needs a Wok When You Have a Satellite Dish?
    Just a little bit more expensive.
  • Not a satellite?! (Score:4, Insightful)

    by bobbagoose (1070066) on Thursday March 01, 2007 @08:13AM (#18192668)
    Can this actually be considered a satellite transmitter as it is only beaming signal to a receiver on top a hill?
    • by Comboman (895500)
      Can this actually be considered a satellite transmitter as it is only beaming signal to a receiver on top a hill?

      You are correct, it is not a satellite transmitter. Both the original article and the Slashdot post make the common mistake of calling any parabolic dish antenna a satellite antenna, even when no satellite is involved. Conversely, many satellite antennas (both transmitting and receiving) are not parabolic dishes at all (think of a handheld GPS or satellite phone), but the most commonly seen (t

  • by 140Mandak262Jamuna (970587) on Thursday March 01, 2007 @08:27AM (#18192708) Journal
    Among the many solar cooking devices shown in that site [solarcooking.org] are a few solar cookers made from discarded sattelite dish antennae [backyardnature.net]!!!!!

  • by rodney dill (631059) on Thursday March 01, 2007 @08:34AM (#18192740) Journal
    ...and after watching once, people feel the need to tune back in an hour later.
    • I've never understood this complaint with Chinese food, mostly because I've never experienced it myself. Yeah, it doesn't sit in your stomach like a lead weight, but it's not like you're hungry an hour later, right?

  • As if millions of Slashdotters all cried out in unison, "Hey, I gotta try that!"

  • Wow, not only can it cook up a good stir-fry but it can also make a satellite dish.
  • It wokked right with a lot a work!
  • "A group of us wanted to connect our computers to each other and then we wokked out a way to get of getting the signal between two points," he said.
  • So... a curved bit of metal can function well as a curved bit of metal? I've got a flat bit of metal here. Wonder if I can use it as some kind of plate?
  • by kanweg (771128) on Thursday March 01, 2007 @09:25AM (#18193022)
    you can use a wokkie-tokkie

    Bert
  • I saw guy on TV the other day who visited the Amazonian jungle, and he said that this is more or less how the local people there watch the World Cup.
  • I hope 45 South doesn't transmit pron cause it's Not Safe for Wok.
  • I have a couple of DSS dishes, the round kind, not the old primestar type. Does anyone know of a site with a good 2.4GHz antenna design based on them? Pref. with a biquad?

Mirrors should reflect a little before throwing back images. -- Jean Cocteau

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