Wireless Witch: DIY Wireless Extenders Put to the Test

Any time I review a wireless extender, some reader typically leaves a comment about just making a homemade extender to avoid paying for one. I finally decided to build my own wireless extender and compare its benchmark results to those of "store-bought" ones. The results? As you'll see, they were bit of a mixed bag, but it's definitely an interesting DIY project.

There are plenty of videos and articles on the Internet about making a DIY wireless extender. The two primary methods include creating a "cantenna"—an extender made from a can and a few additional components; and a parabolic reflector—available as a template cut-out from freeantennas.com. I opted to go with the reflector solution. This consists of printing out a template, which you can download from the site, on hardy media such as business card stock paper and then cutting out and assembling the template in the shape of a parabola lined with aluminum foil.

I downloaded the template, printed it on heavyweight paper, and assembled the extender according to the website's instructions. It's more time-consuming than setting up a typical purchased wireless extender, but the experience was kind of arts-and-crafty fun. I made a pair.

I wanted to test two scenarios: The first was to determine how much the parabolic extender (called Windsurfer) increased signal strength and range with a router that had external antennas. And second, I would test whether the homemade extender had any effect on routers that have internal antennas—as do most high-end routers these days.

I tested using Trendnet's 450 Mbps Concurrent Dual Band Wireless N Router (TEW-692GR) , which has three external antennas, and then with Linksys's Smart Wi-Fi AC 1750HD Video Pro EA6500 ($85.95 at Amazon) which uses internal antennas only.

For the Trendnet device, I poked holes on the top and bottom of my homemade extenders and slid them onto the router's left and right antenna, leaving the middle antenna alone.I then ran a few benchmarks using Ixia's IxChariot to test throughput and inSSIDer to test signal strength. First I ran tests without the Windsurfer extenders and then with. Here are my results:

In the same room, I had slight signal strength gain with the extenders, but performance was pretty much the same with or without. At 50 feet, I see quite a noticeable gain using the extenders. Signal bars first were at 3, then I went down to 2. Unfortunately though, the wireless signal was not consistent, and eventually my connection dropped—that's why I couldn't run throughput tests.

So, yes, the extender did help at 50 feet, though the connection was flaky. That may be due to all the RF interference where I tested.

Extending Routers with Internal Antennas
It might seem that you would only benefit from this type of homemade extender on routers with external antennas. Most premium consumer routers are now shipping with internal antennas. I duct-taped the pair of extenders to Linksys' Smart Wi-Fi AC 1750HD Video Pro EA650 ($85.95 at Amazon) router, which has internal antennas. Here's what I saw:

In the case with the router with internal antennas, the extender did not help the signal at 50 feet away and actually seemed to impede performance. But it significantly improved throughput at shorter ranges.

Making a parabolic reflector is certainly cheaper than buying a Wi-Fi extender from a vendor. I only had to buy business card stock paper ($9.99), aluminum foil ($2.00), and an X-Acto knife ($2.00). But you may have all of this stuff lying around anyway. Manufactured extenders can range from $40 for BearExtender's PC Long Range 802.11n USB WiFi Booster up to $120 for D-Link's Amplifi DAP-1525 Wi-Fi Booster (a device that we rated only as "Fair."). So there is definitely a cost advantage with homemade units.

Based on my testing, however, you don't get that big a boost with a homemade parabolic reflector at 50 feet and beyond, although I did read that if you make the template larger to make a larger parabola and reflector, you can perhaps boost the signal a bit more. How willing you are to put up giant foil-coated reflectors in your home to save a few bucks probably says a lot about you, however. As you can see from the table below, the purchased extenders were little more effective in boosting a router's signal at further distances, such as BareExtender's which still managed decent throughput at 75 feet.

Click here for manufactured wireless extender throughput results

The Verdict
Freeantenna.com's homemade extender is easy to make, and DIY types or those looking for a cool science project may find it just the thing. I personally found it tedious cutting out the figures from the template and a little tricky getting the thing assembled, though. If you have the time, have perhaps an older, or lower-end router with external antennas, and want to save a few bucks, it's worth testing it out—especially if you're looking to boost signal over a short range. If you need consistent signal boosting in a larger area, or for a small business, you'll likely want to stick with a purchased Wi-Fi extender, and preferably one made by the same company that made your router.

Note: In the above two charts, signal strength is incorrectly referenced as "decibels." The measurements displayed are actually in "dBm."