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Who Needs a Satellite Dish When You Have a Wok?
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."
Is a wok parabolic in cross section or is it circular?
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.
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Can you somehow add a ball point pen and chewing gum into making the dish?
MacGyver would just love that!
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.
"Doing what i can, with what i have." ~ Burt Gummer
...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.
If you'd actually read the entire article, which admittedly is a lot to ask, you'd have known that the local TV station used the same setup as an uplink, saving a cool $20.000
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 $10 wok.
Yep the 10$ 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 hat!!At least I got to drink the coffee :)
As long as you make it the right shape, there's no reason why a tinfoil dish wouldn't do the job too.
You should see how thin some dishes on real satellites are.
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In the past, people have also used those circular snow sleds as the basis for building a dish antenna.
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Else the wok rusts out and they're off the air!
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So, basically, depending on how much "a lot of time" is, they may have even made a loss? Time literally _is_ money when an employee or two are doing it. You pay salaries for that time. So having someone figure out the focal point, the mounting, build some contraption to hold the LNB in the right place, etc, can end up costing more than $70 quite easily.
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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.
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Misleading titles? Inflammatory blurbs? Keep in mind that Slashdot is a tabloid.
I think it's here :
http://www.usbwifi.orcon.net.nz/
TV by wok, eh?
Reminds me of the tasty and very useful Pringles antenna.
Geeks and their obsession with food...
What's next? A pizza box server? (no wait... scratch that)
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...I want to cook up some chicken stir fry and watch telly at the same time?
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.
And this is not exactly new, mack in the 1970's we used to use $7 snow sleds to pirate HBO.
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.
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.
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A friend of mine is from New Zealand. They are fiercely independent and patriotic people, much like Mr. Chekov in Star Trek (everything was done first or better in Soviet Union, remember?). Well, the Kiwi's may even have a valid claim on the first Powered Flight. Though Mr. Pearce never claimed to have flown first because he didn't achieve a controlled landing.
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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.
Can this actually be considered a satellite transmitter as it is only beaming signal to a receiver on top a hill?
...and now the image quality is more like...err...sweet and sour? or: what about the signal being chopped?
How about: "I know I just watched the show an hour ago, but I'm hungering to see it again."?
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...and after watching once, people feel the need to tune back in an hour later.
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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?
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.
Yes, woks can be good enough approximations of parabolic cross section. /. 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.
/. article " 4km WiFi Range w/ $5 DIY Antenna ". TFA is mostly the same idea but applied to a different signal in the same GHz range (microwaves).
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 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).
- 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
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This is the effect you see with thin foils in a microwave oven, and has led to the extremely popular misconception that you can't put metal into a microwave. With a minimal bit of observation anyone will see that the entire microwave enclosure IS metal and reflects the microwaves just fine without significant absorption. The only problem is with thin foils which are incapable of efficiently reflecting the microwaves.
I haven't calculated how efficiently tin-foil might reflect the high power radio waves mentioned here, but wouldn't put money either way without checking. (I haven't yet read the fine article, so I don't even know what power levels we're talking about).