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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?"
I think that the range of WiFi that we have right now is good enough. 100 meters? Stop complaining.
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.
- Posted via Danger HipTop2 / T-Mobile Sidek!ck II -
...my tinfoil hat is not for sale, kind sirrah.
"Made up/misattributed quote that makes me look smart. I am on
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.
I think the "USB antennas" you're talking about are really USB wireless adapters mounted at the focal point of a parabolic reflector.
"I'm feeling lucky" for "USB parabolic antenna" gave me this.
You could always get one of those little WAPs (like the size of a deck of cards) and set it up as a repeater. You could probably hook an antenna up to one of those. Sorry, I'm too lazy right now to look up any specifics.
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.
But signal loss in the direction of propagation isn't is it? Also are the strengths of the two transmitters the same? I would think the laptop might use a less powerful transmitter. Not sure what other factors there might be. I'm not sure of all the issues involved, nor do I fully understand the concepts brought up here.
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.
I'm faced with the same problem and found a few ways around it.
I have a public network 3.3km away on a hill with a 500mw amp, I can sometimes see it but too week to connect. so I did some shopping.
In total I got 2 usb wlan adaptors 3 pcmcia cards and 1 ap,
I found that some of the old devices out performed the new ones.
an asus wl-167g(usb g) can't see a network 3houses down, where a netgear ma111(usb b) can see half the street.
Then I made a usb pringles antenna by inserting the ma111 usb adaptor 1/4 wavelength from the base at about 3-4cm depth. then I could probe networks over 2km away. both the asus and netgear uses an internal hirose antenna connection inside if want to add a antenna, you just need to crack open the case. You can also use a small tripod from a camera to help aim it. On mine the tin, tripod and usb wifi can be disasmbled and pack away in my laptop bag.
Another idea I had was to setup an AP to connect to the other wifi network then my laptop to it,
[laptop]-[ap]----[other ap]-[internet...
most good AP let you connect to other AP(wds). Upgrading the antennas is easier and i've had my AP running off a 9v battery a few times before.
If you using windows I've found using 3rd party wifi clients hold better connections over the XPSP2 zero config thingy
My main tip would be to play around and see what works for you , or just go buy that wardriving kit and save time(and money).
[sVen]
All internal MiniPCI Wireless lan cards have 2 attachments for an antenna. I suggest making some homebrew wire that can exit the laptop somewhere to an external antenna, It might look ugly and decrease range of your card when not using an external antenna. But its a place to start.
There is no "USB Wifi antenna" on the market, but just USB wifi adapters.
By the way, laptops (whether Centrino or not) use a quite big antenna hidden into the diplay/cover case. And this is bigger than any other "normal" external wifi antenna.
The only good thing to be done is to ask manufacturers to add an external antenna plug, as they used to do for cell phones.
Maybe Computers will never be as intelligent as Humans.
For sure they won't ever become so stupid. [VR-1988]
a lot of PCMCIA wifi adaptors will have a small round plastic plug hiding a standard-ish socket for plugging in an external antennae. this is particularly common on the older buffalo cards - you can get nice, neat external antennae for them that are small enough to fit in your laptop bag and roughly double the range.G Hz_Wireless_Indoor_Omni_Antenna__WLE_NDR.aspx for an example: I had one of these with a 1st gen 802.11 buffalo card and it worked very nicely.
this is going to be way neater than cracking open your laptop and soldering something onto the antennae built into the lid of your laptop.
see http://l8shop.net/Products/Buffalo_AirStation_2_4
Check this site: http://www.hyperlinktech.com/web/1.13_custom_cable s.php
You can get a short adapter cable with a connector that fits your internal card (probably U.FL) and runs to a N or RP bulkhead you can install somewhere in your laptop if you can find the space. I think the Kensington lock slot should have enough empty space behind it, you should be able to drill a hole. Now you have a connector for you laptop antenna, at this point check the same site I linked above; they have portable external antenna options.
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
Any WiFi hardware must be FCC certified, and certification is always performed on the radio (WiFi card) and the antenna as a whole. An (external) antenna that is not explicitly FCC certified for a particular card is verboten.
Antennae in laptops (just open the LCD bezel to see for yourself) are relatively big -- most of the time bigger than what you'd be willing to take with you in your laptop bag :-).
Using a directional antenna will mostly buy your radio more output, but it would require you to point it in the proper direction (which may not be that easy). Unless the other side (i.e.: the access point) is also using a directional antenna, it won't buy you much though.
Okay... I'll do the stupid things first, then you shy people follow.
[Zappa]
It amuses me to see Centrino adverts saying "Internet Anywhere" or some such. Point of fact, it's not. Between where i'm sitting and my house 3km away, there are 3 hotspots, yes i've counted. It's just not everywhere at all, and if you do find it, only 1 in 20, or so, of them are actually open (whether intentionally or not). Services like Netvigator (who now have a new name, I believe) DO provide internet anywhere. Pity it's not 802.11g, eh?