wifi amplification?

March 10, 2005 1:59 PM

Is there a way to amplify a weak wifi signal?

I have a pc laptop with a built-in wireless card ("integrated wireless"?). There is one place that I'm often working where I can intermittantly receive one or two wifi signals. Even when functionally receiving a signal, Windows will call the signal strength "no signal" and the reception will go in and out. Is there some way that I can boost this signal from where I am? (I don't have access to the source. Please no moralizing.)

An additional note: A friend's laptop (a small Dell computer) in the same location will receive the signal pretty consistently.

posted by nobody to Computers & Internet (16 answers total)

Is your friend using a non-integrated solution (ie a wifi card)? If so, you might have luck going the same route. Maybe try using his card in your laptop before ponying up for a card of your own (though they have gotten quite cheap), to verify that this is indeed the issue.
posted by PinkStainlessTail at 2:04 PM on March 10, 2005

Response by poster: I'll have to check, but I think she has the sort of wireless receiver that's built into the Intel chip. (Am I making that up? Has advertising tricked me into thinking that exists?)
posted by nobody at 2:07 PM on March 10, 2005

The only way to increase the signal to noise ratio of an incoming signal where you don't have access to the transmitter is a better antenna and/or a better built (less internally noisy) receiver.

Since, nowadays you generally don't find all that much gain spending your money on a receiver, you'll need to step up to a better antenna. That would mean something more directional, usually.

Now, for signal going out, you can again, either go with a better antenna, or pump up the output gain.

Sooo, yeah, better antenna for sure.

Note that since your card also broadcasts, going with an antenna with too much gain is illegal; although if you're not boosting the power from the card to it I would REALLY doubt the FCC could care at all.

One thing to know is that not all 802.11 adapters have jacks for external antennas, and more to the point, even when they do they are almost always REALLY odd looking things so you WILL be buying adapters.
posted by shepd at 2:22 PM on March 10, 2005

Response by poster: If the laptop in question has "integrated wireless," does that mean I would have to get a new card and an antenna, or is there some way of gerry-rigging an antenna onto the machine?
posted by nobody at 2:31 PM on March 10, 2005

I don't think it's literally built onto the same chip--as I understand it, "Centrino" is really just a brand name for when certain Intel processors and WiFi chips are bundled into the same machine.

More usefully, Walt Mossberg had a review of the Belkin "Pre-N" technology a little while ago that was pretty complementary (that's pay-per-view, so here's another review)--it apparently gives a pretty dramatic boost to throughput and range. You'd need to buy both a base access point and a card for your PC, so it may be more of an investment than you were looking for, but it looks like you can probably get away with under $200 for the pair if you shop around. (I can't vouch for it myself, but I've read several pretty favorable reviews.)
posted by LairBob at 2:35 PM on March 10, 2005

is there an easy step by step out there to building a ridiculously powerful antenna for your wireless router?

easy == no math, not much soldering, no hinky jinky tuning.
posted by fishfucker at 2:51 PM on March 10, 2005

Read this feature on the Pringles can wireless antenna as well as the links therefrom.
posted by matildaben at 2:55 PM on March 10, 2005

Integrated wireless means the radio chip is on the motherboard (or possibly on a separate board hidden inside), and the antennas are somewhere in the laptop's casing.

If you got a separate card, it'll usually have the antenna hidden inside the bulge that sticks out of the laptop. I have no idea whether that will give better reception than your integrated antenna. Although as mentioned, some do offer the ability to hook up a larger external antenna.

Another option is plugging in a wi-fi repeater halfway between you and the source, although that may not be an option.
posted by cillit bang at 2:57 PM on March 10, 2005

An easy plan for building a ridiculously powerful WiFi antenna is the Deep Dish Cylindrical Parabolic Template. This probably does not really answer the question because I have my doubts as to how you would get it to work with an internal wireless adapter. The location of the antenna within the reflector is crucial. However, I can attest to how effective the device is. I built one out of a piece of scrap metal window screen, cardboard, and hot glue for an external USB WiFi adapter with brilliant results.
posted by KrustyKlingon at 3:13 PM on March 10, 2005

Are there no peripheral antenna solutions to this problem? I have the trouble in my house, reaching from my office to my partner's on the lower level. We are very close, but wall/floor/window between (like, 3 meters out and 2 down). The card downstairs doesn't have an antenna jack (which is stupid).
posted by Goofyy at 8:26 PM on March 10, 2005

Even better then the the Pringles can wireless antenna, a link from that site the tin can waveguide, the antenna I bought for my tower computer is mediocre/crappy, even thought my laptop picks up a nice signal in the same room as the tower. So, perhaps I'll try this tin can thing.
posted by edgeways at 11:57 PM on March 10, 2005

To throw in my two cents...

If you don't want to go through the hassle of building your own, just buy the Cantenna. It's more expensive, but it is pre-built. There are probably others out there, and they may not be quite so expensive.

But... for your specific problem... Find out what kind of wireless card (or chipset) is in use in your laptop, and get a wireless configuration utility for that wireless card. Then, in the Windows Wireless Configuration, under advanced settings, uncheck "Use Windows to configure my wireless network settings". The Windows utility sucks, and will drop your connection unnecessarily.

Alternately, you could purchase a wireless bridge that acts as a booster between your laptop and whatever other Wireless device you re attaching to.
posted by stovenator at 1:01 AM on March 11, 2005

Response by poster: Thanks for all the advice. It doesn't look like my computer has any place to plug in an antenna, but wireless cards look inexpensive (my friends' mentioned above is built into the laptop so I couldn't just try that out).

If I wanted to try a wireless bridge, does anyone have any suggestions for quality/price/returnable-if-it-doesn't-do-the-trick? (I live in nyc).
posted by nobody at 7:44 AM on March 11, 2005

I'm not certain about price and quality, but Staples and Radio Shack are always good bets for the old "return-after-you-try-and-buy" no-fee rental program. Also, it may be worth considering buying a USB client. I have an old Linksys WUSB11 that consistently seems to receive a stronger signal than a variety of different PCMCIA cards I've owned and/or tested. I don't know if they contain larger antennas or if it's just that the cable allows you to move it around until you find a sweet spot, but it's worked for me.
posted by Sinner at 9:50 AM on March 11, 2005

It seemed to me, when I was pricing them, that devices marketed solely as bridges or repeaters are more expensive than a do-it-all AP. I know the Linksys WAP11 and the newer WRT54G can both act as repeaters, bridges, or wireless clients.

I've always had good luck with Linksys' products, but they are cheap.

Due to FCC requirements, most cards and even APs that have connectors have something proprietary, to keep you from modifying it in the first place =). There are parts available, but they tend to be pricier than standard stuff.

Also, keep in mind gain on either end of the connection (AP or client) will help in both directions.

A better antenna will most likely help the situation, and it'd be easier to add the antenna on the AP end. I had an old 3Com AP (ancient!) that had an internal antenna that was basically a printed circuit board with some traces on it. Going to an external antenna drastically improved my reception throughout the house.

The Pringles can antenna is functionally a Yagi, and provides incredible gain, but sacrifices coverage. It has a very small RF pattern, and would only help in the one area you aim it at. There are flat panel antennas that have a 120-180 degree spread and provide modest gain. That might be ideal for your situation.

Also, the newer Linksys APs (the WRT54G rocks) have, I believe, standard N-type connectors. It may be worth it to upgrade the AP and find a proper antenna. They go new for about 60 bucks.
posted by kableh at 1:31 PM on March 11, 2005

Response by poster: I didn't see anything on the Staples or Radioshack sites, but a google search came up with this
"Wireless LAN Pocket Access Point", which looks great because of how portable it is. Should I trust it, seeing that I probably won't be able to return it easily if it doesn't help?
posted by nobody at 2:38 PM on March 11, 2005