Recommendations for a good antenna.
May 22, 2010 10:27 AM Subscribe
Any suggestions for an antenna for my desktop wireless networking card?
It's a dual-band N card (2.4 and 5 ghz) Linksys with two RP-SMA antenna connectors. Both of the stock antennas work on the 2.4 and 5ghz bands simultaneously, I think. Not sure if that's common.
Directional is fine--in fact, probably better. I'd like to spend under $100, and since I'll be ordering it online, I'd really like to avoid getting a dud that doesn't really perform better than the stock antennas even though technically the manufacturer managed to get it rated with a higher gain.
(Did I use the word "gain" right in that sentence?)
I'm renting a small cottage behind a larger house, and we're trying to share the wireless signal coming from inside the house. My laptop can get online, but my desktop card is too weak to even connect. (It can see the network, though.)
It's a dual-band N card (2.4 and 5 ghz) Linksys with two RP-SMA antenna connectors. Both of the stock antennas work on the 2.4 and 5ghz bands simultaneously, I think. Not sure if that's common.
Directional is fine--in fact, probably better. I'd like to spend under $100, and since I'll be ordering it online, I'd really like to avoid getting a dud that doesn't really perform better than the stock antennas even though technically the manufacturer managed to get it rated with a higher gain.
(Did I use the word "gain" right in that sentence?)
I'm renting a small cottage behind a larger house, and we're trying to share the wireless signal coming from inside the house. My laptop can get online, but my desktop card is too weak to even connect. (It can see the network, though.)
The best would be low cost antenna locally which could easily be returned if inadequate, then that might be a good strategy. But you say you need to order online, which makes this idea less feasible.
With the caveat that my research is a year out of date or so, my inclination would be to recommend a different approach. As you say that your laptop connects on its own, this tells me that we're not talking huge distance here. One approach is to buy a USB wireless adapter and a long usb cable. Using a Stumbler app, (I assume you're using Windows?) on the laptop, you can move around and find where there is good signal. Presumably you know where the router is (in the main house), and you know where the clearest line of site from your cottage is? Hopefully you will be able to position the usb adapter high enough, or close enough to a window to get a good signal.
I've had a lot of experience with long range wifi, and third party antennas, and I know that with each new connector there is automatically some loss involved. There is a lot of hit and miss with matching antennas with cards, and there can be a lot of loss depeding on the cable and connector you use. We've always had crap reception from PCI based adapters.
I've used Pringle's can antennas ("Cantenna" brand name) which work okay. But since they are very highly directional, they need to be well fixed so they don't move. Also, if your computer is too far away from your "window" so to speak, then using enough cable to get your antenna in a good place would cause too much loss. In my experience, a very cheap USB adapter on a long cable can be put up very high, or in a window, and then you don't need to worry about antennas, and connectors etc, and the cost is less. A long cable gives you the flexibility move it around and find a good location.
Also, do you know what flavor the main house router is? If it's only a G band router, then you can certainly get away with an older G adapter which would be cheaper. Depending on the distance covered, it may not matter anyway- in other words, your connection will never get above G speeds anyway, so there's no point spending the extra money on a newer flashier adapter.
These crazy people have used commonly available noodle strainers and other parabolic meshed items to amplify the signal- at a very low cost. Again, that might not be needed at all. It may be that the USB connector will be fine on its own. (Actually, I've followed those people's antics for many years and have a great deal of admiration for their approach and results)
Hope this is helpful.
posted by MacChimpman at 12:57 PM on May 22, 2010
With the caveat that my research is a year out of date or so, my inclination would be to recommend a different approach. As you say that your laptop connects on its own, this tells me that we're not talking huge distance here. One approach is to buy a USB wireless adapter and a long usb cable. Using a Stumbler app, (I assume you're using Windows?) on the laptop, you can move around and find where there is good signal. Presumably you know where the router is (in the main house), and you know where the clearest line of site from your cottage is? Hopefully you will be able to position the usb adapter high enough, or close enough to a window to get a good signal.
I've had a lot of experience with long range wifi, and third party antennas, and I know that with each new connector there is automatically some loss involved. There is a lot of hit and miss with matching antennas with cards, and there can be a lot of loss depeding on the cable and connector you use. We've always had crap reception from PCI based adapters.
I've used Pringle's can antennas ("Cantenna" brand name) which work okay. But since they are very highly directional, they need to be well fixed so they don't move. Also, if your computer is too far away from your "window" so to speak, then using enough cable to get your antenna in a good place would cause too much loss. In my experience, a very cheap USB adapter on a long cable can be put up very high, or in a window, and then you don't need to worry about antennas, and connectors etc, and the cost is less. A long cable gives you the flexibility move it around and find a good location.
Also, do you know what flavor the main house router is? If it's only a G band router, then you can certainly get away with an older G adapter which would be cheaper. Depending on the distance covered, it may not matter anyway- in other words, your connection will never get above G speeds anyway, so there's no point spending the extra money on a newer flashier adapter.
These crazy people have used commonly available noodle strainers and other parabolic meshed items to amplify the signal- at a very low cost. Again, that might not be needed at all. It may be that the USB connector will be fine on its own. (Actually, I've followed those people's antics for many years and have a great deal of admiration for their approach and results)
Hope this is helpful.
posted by MacChimpman at 12:57 PM on May 22, 2010
A couple of different ways to look at the problem: since you already get a good signal on your laptop, you can use internet sharing on it and allow the desktop to go through it. Or buy another router and place it beside your laptop (since you get a good signal there). It becomes a client of the router in the house and serves out IP addresses to your cottage.
posted by PickeringPete at 2:04 PM on May 22, 2010
posted by PickeringPete at 2:04 PM on May 22, 2010
You say that your card is both 2.4 and 5 GHz, but what is the network that you are connecting to actually using? 802.11 (b) and (g) use 2.4 and 802.11 (a) uses 5. If the network you are connecting to doesn't actually use both, that will make selecting an antenna much easier since you're only dealing with one band. (Although many designs are dual-band, made easier because the two are close to being multiples of each other.)
There's no reason for you to pay very much — if anything — for this project.
If you're the least bit handy, you can build one of the venerable "Cantenna" or "Pringles Can Antenna" designs. They're well-tested and offer about ~12dBi gain. You can build them out of pretty much any sort of metallic cylinder: coffee cans, liquor bottle sleeves, etc., or you can get a commercial version. Pretty much the only critical measurements are the length of the internal radiator and where you put it along the length of the tube, although the dimensions of the tube will affect the radiation/reception pattern. They fall under the general heading of "waveguide" antennas, if you'd like to read up on how they work.
You can also get Yagis for the wifi bands, although these are harder to DIY and tend to be a bit more expensive as they have more critical dimensions. They also tend to be made for outdoor installation.
(N.B.: For a passive device — one that doesn't contain an amplifier — directionality and "gain" are basically the same thing. The higher the gain, the more directional the antenna. Just something to keep in mind. Some people seem to think that high-gain antennas are just inherently 'better,' without understanding the inherent tradeoff. There is no free lunch in antenna design.)
If you are willing to give up on using the wifi card currently in your computer and instead use a USB one, there are clever hacks which put small USB wifi dongles in the center of parabolic dish antennas for very high gain. They also have the benefit of near-zero feedline losses, since the connection to the computer is USB rather than coax.
posted by Kadin2048 at 7:36 PM on May 22, 2010
There's no reason for you to pay very much — if anything — for this project.
If you're the least bit handy, you can build one of the venerable "Cantenna" or "Pringles Can Antenna" designs. They're well-tested and offer about ~12dBi gain. You can build them out of pretty much any sort of metallic cylinder: coffee cans, liquor bottle sleeves, etc., or you can get a commercial version. Pretty much the only critical measurements are the length of the internal radiator and where you put it along the length of the tube, although the dimensions of the tube will affect the radiation/reception pattern. They fall under the general heading of "waveguide" antennas, if you'd like to read up on how they work.
You can also get Yagis for the wifi bands, although these are harder to DIY and tend to be a bit more expensive as they have more critical dimensions. They also tend to be made for outdoor installation.
(N.B.: For a passive device — one that doesn't contain an amplifier — directionality and "gain" are basically the same thing. The higher the gain, the more directional the antenna. Just something to keep in mind. Some people seem to think that high-gain antennas are just inherently 'better,' without understanding the inherent tradeoff. There is no free lunch in antenna design.)
If you are willing to give up on using the wifi card currently in your computer and instead use a USB one, there are clever hacks which put small USB wifi dongles in the center of parabolic dish antennas for very high gain. They also have the benefit of near-zero feedline losses, since the connection to the computer is USB rather than coax.
posted by Kadin2048 at 7:36 PM on May 22, 2010
If you are bound and determined to tackle the problem as one of improving your antenna on your desktop, try Googling the domain lifehacker.com with the keywords antenna+wireless. Solutions of varying complexity ranging from free.
posted by PickeringPete at 7:27 AM on May 23, 2010
posted by PickeringPete at 7:27 AM on May 23, 2010
If you really want to understand your options, technically, I suggest you take a glance through "Wireless Hacks" by Rob Flickenger. O'Reilly Press. ISBN 0-596-00559-8. But, as I said in my earlier posting, I would build on the fact that you already have a connection at one point in your cottage, at least. And if you ever move, another router is handy and they are cheap. Just my 2 cents.
Good luck.
posted by PickeringPete at 7:32 AM on May 23, 2010
Good luck.
posted by PickeringPete at 7:32 AM on May 23, 2010
This thread is closed to new comments.
posted by hungrysquirrels at 11:01 AM on May 22, 2010