Cantennas and Better Wireless Signals

Getting a good wireless signal to your laptop in various situations is a combination of science and art that may include cantennas.

The highly useful but 'caveat emptorish' Wikipedia, as of 5:07 pm, CST, today, says a cantenna is a "directional waveguide antenna for long-range Wi-Fi used to increase the range of (or snoop on) a wireless network. Originally built using a Pringles potato chip can, a cantenna can be constructed quickly, easily, and inexpensively using readily obtained materials...The term 'Cantenna' originally referred to a product sold by Heathkit Co. in Benton Harbor, MI."

Sometimes your standard laptop wireless configuration (built-in, PC card wireless adapter or USB wireless adapter) gives you only a weak wireless connection, or possibly no connection even though there's a wifi access point in the area. That happens to be the case for my daughter who is a senior in college. She has no internet access in her apartment (long story) but she is very close to a laundromat that has a free wifi hotspot. Sometimes she gets a weak wifi signal, but it sometimes won't connect and other times cuts out after very short connection times.

Some searching was done on the net for answers to this weak wifi signal problem, and the situation was discussed with a few people. We figured out a couple kludges, but didn't come up with what seemed like a clean solution.

At the NEW NET gathering on 02 Jan 02007 we discussed cantennas and the scarcity of usb wifi adapters with external antenna connectors. After kicking around a couple ideas and looking at the Wireless Hacks book, Andy M did some online searching and came up with the perfect solution.

I called the company that sells the perfect solution, Air802 LLC, and discussed combinations of their equipment that should work well for my daughter. We ended up choosing the wireless USB Adapter 802.11b/g With External Antenna Connection #USB-ADG-1, the 2.4 GHz Yagi 10dBi Antenna #ANYA2410, and a 10' coax adapter cable with an N connector on one end to go to the antenna and an RPSMA connector to go to the USB wireless adapter. The gentleman I talked to was friendly, helpful and answered all my questions. He said he started selling the USB wireless adapters with the antenna connector because boat and RV owners kept asking for them.

Next week we'll see how well this solution works. I'll be in California visiting my daughter and will set up the equipment to try and provide her with a net connection. If for some reason it doesn't work well for her situation, we'll just experiment with the equipment for myDigitechnician purposes in Wisconsin. If it works very well, it might even make sense to recommend a similar setup for some of the myDigitechnician clients who have problems getting good wireless signals on their home networks.



Anonymous Kristine said...

I'm very interested in how this turns out as I too have difficulty in getting my internal wireless to pick up a good signal frequently. I'd especially like to know how well the card and included antenna alone work.

Thanks for the post.

11:56 AM  
Blogger myDigitechnician said...

FedEx delivered the usb wireless adapter and Yagi antenna late yesterday (10 Jan), so we haven't had a chance to play with it too much. The Yagi hook-up definitely gave us a good strong signal. I'll try to get some quantitative perfomance data comparing the 802Air usb wireless adapter with it's included 5dB antenna (about 6" long) to the 802Air usb adapter with the 10dB Yagi antenna and to another usb wireless adapter that has no antenna (DLink, I think). Two limitations regarding that quantitative data are limited time to test the set-ups (I have to leave the equipment/my daughter's apartment/northern California tomorrow morning...), and I don't have sophisticated wireless performance software/hardware to accurately determine the performance with each of the three setups.

One clarification regarding your comment, Kristine, is that you mentioned a "card" and included antenna. If you are referring to a PC card (PCMCIA) wireless adapter, you should note that the wireless adapter mentioned in this post is a usb adapater rather than a PC card adapter.

The performance of the 802Air usb wireless adapter and included antenna vs. a laptop with built-in antenna will depend on what laptop you have. Built-in wireless performance can vary greatly from laptop to laptop, so it's difficult to say how much better the 802Air usb adapter will be compared to the laptop's built-in wireless hardware. But if you're considering buying a usb wireless adapter, I'd highly recommend the 802Air adapter (only $36, plus shipping).

12:18 PM  
Anonymous kristine said...

Sorry, I meant USB. My laptop is an HP Pavilion with an internal wireless setup w/ no antenna connection. I'm looking at USB solutions (especially with removable antennas since I think that would offer me the most versatility in antenna options). Funny, I live in Northern CA too, but not as far North or West as your daughter. Thanks for the info and I checked out the other post on this too.

12:07 PM  
Blogger myDigitechnician said...

Kristine - If you have any questions about the Air802 equipment, feel free to email me; bob [at] gmail dott com. Or call Air802 at (630) 428-3108 -- the guy I talked with was very helpful and friendly. Unfortunately, because the equipment arrived right at the end of my visit to beautiful northern California, I didn't have time to do any comparison testing between signal strength from the external 10 dB Yagi antenna and the 5 dB antenna that comes included with the USB wireless adapter from 802Air. If you want to take the stepwise approach, you could first order just the usb wireless adapter. If that didn't give a strong enough signal, then you could get the Yagi and adapter coax cable to get a stronger signal. Good luck!

7:18 PM  

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