Improve the range of your wireless keyboard or mouse.

I bought a really cool wireless media center keyboard with an onboard trackball mouse, so I diden't need to sit at a table with a mouse, mousepad and a keyboard while enjoying my media center. The plan was that i would be able to relax in my sofa while surfing the internet by using this clever unit.

But oh no! On the cardboard box there was written that the range of the keyboard should be up to 5 meters, but it was at best 2 meters. Not long enough to be used as I intended.

Then I noticed something on the cardboard box. On a sticker there was written that the keyboard used the radiofrequency of 2.4 ghz. That's the same as wireless LAN!!!

The cardboard box
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Then I remembered that I once saw someone who had soldered an external antenna to his WiFi USB dongle, and I started to wonder if I could do something similar. I found an old Linksys accesspoint that I once bricked. I opened it up and removed one of it's two antennas:

The bricked Linksys accesspoint
click to enlarge...

Then I took apart the USB keyboard dongle. This was easy since it was only clipped together, and could be prised open with a flat screwdriver. The core of the antenna cable was soldered to the start of the internal antenne which was integrated in the dongle PCB. The shielding of the antenna cable was soldered to the ground on the PCB. To get access to ground on the PCB, I just scraped off a bit of the green top coating at a suitable area:

The USB dongle with the antenna soldered to the PCB
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Here's an overview of the Linksys accesspoint and the USB dongle:

An overview of the accesspoint and dongle
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Heres the dongle after i filed a small hole in the cover to the antenna:

The dongle with antenna
click to enlarge...

Finally to the good news!

The range was improved with at least 400%
The keyboard works 15 meters away from the antenna!
I can now lean back and enjoy my media center, with only one HID device.

Nov, 2006. Written by David