Random Access Science

Geophysics, Glaciology, Computer Science and everything inbetween

Trying Out the Alfa AWUS036NH on Crunchbang Linux

Background

I travel a lot for conferences and workshops as part of my PhD. Most hotels claim to have “High-speed internet” and WIFI but most of the time that is a overstatement. So recently I bought the Alfa AWUS036NH long-range USB adapter. It is simply a USB network card with a 5dB antenna that will boost the number of networks you can access. So now even if you get the room farthest away from the hotel access point you may still have a change to connect.

It’s plug and play

On the website (bought if off amazon.co.uk) they claimed it would work on Linux 2.4/2.6. My current kernel is 3.10 so I was a bit afraid it would not work. Plugged it in and it was ready… That was a first. Depending on your system you may need to install the Ralink firmware (on debian: apt-get install firmware-ralink). I did have some problems getting access to networks on kernel 3.2.0 but after the switch to 3.10 everything was fine.

The card takes a minute or so to “warm up”. After that I was able to see about three times the number of networks with the 5 dB antenna. I also bought a 9.5 dB antenna just because I had to try it out. It is massive (There wasn’t any scale on the promotion pictures). It is massive! About the same length as my 13” macbook air. If you didn’t look like someone trying to crack WIFI passwords before you will with this.

Does it work?

I am quite impressed with the device. Allowing the adapter to be on for about 5 minutes I got the following statistics using the list in the network manager.

  • build-in Macbook Air WIFI: 7 network,
  • Using the 5 dB antenna about 31 network.
  • Using the 9.5dB antenna: 39 networks

So not that big a difference with the large antenna but it still makes a difference. The list of available networks does seem a bit unstable. When connected to a network the list shrinks but that is perhaps because some power is used on the current connection.

Conclusion

Do I recommend the Alfa AWUS036NH for linux users? YES, it great. Do I recommend the 9.5dB antenna? Well if you think you need it then yes otherwise it is quite large and removed a lot of the portability of the device. Also with the large antenna the device will tip over because of the weight. You can find a “stable” position where it will stand but the smallest push will tip it. But that is a small price to pay and can be fixed with a piece of paper under the antenna. I also do not quite know how it is to fly with the device. I am sure it will not be a problem but you may get pulled over in security to explain the large antenna you have in your carry-in :)

Update: I have now tried the device a couple of places. At a random coffee house in Helsinki (Finland) I got 14 networks using the build-in device and 27 networks using the 5dB antenna. So quite a difference. I also tried putting the device in my carry-on and did not have any problems. I also experinced that the device uses a lot of power. So if you run in on a laptop expect that you battery life will decrease by perhaps 30% – 50%.