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Portable Wi-Fi Antenna for Centrino Laptops?
Quinthar asks: "For years I've been reading of amazing extensions to wifi-range, but they always seem to include external hardware rather than what's built into regular laptops. As wifi makes it almost everywhere, is there anything I can use to eek out extra coverage in the coffeeshops? I've read of USB antennae -- are these snakeoil? If not USB, how else can I plug a real antenna into a simple Centrino chipset without the hassle of an external card? My dream would be a tiny parabolic dish with a tripod that folds up neatly. Does such a thing exist? Can I hold a Pringles can up to the right spot and expect results? Basically, what are my options, and which do you recommend?"
Yes, actually. I built one, and it works quite well. I have only bothered getting signals from a mile or so, but it should work up to two or even three.
Wonder what the public key field is for?
reflectors don't work unless their diameter is at least on the order of the wavelength you're trying to reflect. for 802.11b/g that's about 12cm - way bigger than most people would like to carry around.
A better alternative is the modern waveguide cantenna design - far more compact than the original Yagi pringles can designs.
Here's a small dish antenna that works wonders, and you can make it yourself. You won't be able to replace the internal antenna in your notebook though. Usb antenna? Pure B.S.
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Remember that the 100M is under rather good conditions .Also 100M can be a rather annoying tether if you have to work 101M + away from your router
The only things certain in war are Propaganda and Death. You can never be sure which is which though
Otherwise, how would you connect the antenna to the radio. Plus, no one ever mentions that both sides have to be able to hear each other. No good if your notebook just hears the base but not the other way around.
Antennas generally achieve more gain by giving up coverage. Most stock 802.11 antennas are designed to radiate more or less spherically. Otherwise, you'd have to keep your laptop in a specific orientation to get a signal. Imagine the tech support... "Turn your laptop 20 degrees to the right. Anything now? Hmm. Try propping a book under the left side."
Cantennas get great range because they are highly directional. If I twist my Pringles can more than about ten degrees, the signal drops off to nil. And since 802.11 is a two-way protocol, there needs to be an eqivalent antenna on the far end. Your Yagi won't do you no good if the Omni at the far end can't even reach halfway back to you.
If all you want to do is listen, or send a signal from your house to your barn, cantennas are a good choice. But for a coffee shop?? Probably not. Just buy a laptop with a large antenna. Newer Thinkpads and Powerbooks generally have large built-in antennas.
Despite all this... Does anybody know of a reasonably priced USB wifi device that will accept a pigtail and a homemade antenna? I'd like to attach a large omni to my PCI-less and PCMCIA-less in-car computer.
If you're going to be carrying around an antenna anyway, is there a compelling reason not to get a cheap wireless pcmcia card and use that instead of the internal wireless hardware?
At the very least, that might be a nice way to start. If you're going to modify hardware, better to start with a $15 network card rather than your laptop. Then, if you discover that the external antenna doesn't help you much (because it's a pain to carry around, or because the places you hang out are still too far away from access points), you won't have to worry about returning the laptop to its internal antenna. And, if by some chance you screw up and break something, you'll be stuck with a broken network card rather than a wrecked laptop.
As far as finding some way to improve your reception without modifying the hardware, you're probably out of luck. Outside of building some sort of active repeater (which would be expensive, potentially illegal, and a much bigger pain to carry around than any alternative), it's hard to think of a way improve the antenna in the laptop itself.
If you want to get silly, you could carry around a large (meter size) parabolic dish and hold your laptop at the focus of it. Not very practical, but it could be fun, and is sure to lead to interesting conversations. If you can find an appropriately shaped umbrella and a few rolls of metal tape, you might be able to make a more portable version. It's possible you could even build some sort of passive reflector out of wire, if you know how the internal antenna is oriented or you're willing to jump into a lot of trial and error.
Use one of those cellphone antenna boosters, which of course you adhere to your laptop battery.
Should provide at least the same amount of antenna boost as it does for cellphones.
Beauty is in the eye of the beerholder.
Namely, he still has to pull the antenna wire out of his laptop somehow, and insert it into the can.
I don't understand how the OP thinks he's going to pull this off without some serious hardware hacking.
+++ATH0