WiMax Antenna With Auto-positioning System

[Andrew] certainly brings a bit of a James Bond feel to connecting to your WiMax base station. He built this antenna along with an auto-positioning system to get the strongest signal possible. The device, which appears a bit fragile, breaks down into a nice little case. When you get to your next checkpoint you can set it up and the stepper motor along with an ATtiny2313 will rescan to get you on with your mission as fast as possible. This is one of our favorite antenna builds so far, and we’ve seen a lot of hacked antennas. Don’t miss the action-packed trailer after the break. Continue reading “WiMax Antenna With Auto-positioning System”

Building A Window Mounted Antenna For Your Car

If you’re into ham radio and want it when you’re on the go give this antenna mount a try. [Cirictech] started with a design from the November 2009 issue of QST and added his own fabrication touches. Everything except the antenna itself is available from the hardware store for just a few bucks, and you should be able to complete this project in a flash. This makes us wonder what the antenna for the 47 GHz band radio setup would look like.

How To Replace A Netgear Router Antenna

rp-sma-adapter-installed

a.ntivir.us wanted to use a different antenna for their Netgear mbr624gu WiFi router. Unfortunately, this model comes with an antenna that is not removable. As with other antenna retrofits, this involves no soldering. But because there is already a mounting area for an antenna, no case altering is needed either. After opening the router with a Torx driver it was discovered that the non-removable antenna was connected to the board with a mini rf connector (U.FL). The antenna and its mounting bracket were removed and a U.FL to RP-SMA adapter was put in its place using a washer to secure it to the rear plate of the router. Now any external antenna can be used and the router still looks brand new.

Aspire One External Antenna

IMG_0023-300x225

External antennas on netbooks are notorious, from EEE PCs to the Panasonic CF-R1, but this is the first on an Acer Aspire One we’ve seen. [xRazorwirex] sent in his external antenna hack for the 802.11n capable D150, with the intention of increasing performance, but he says he can’t attest to any change. Unfortunately the lock slot had to be removed, but a small price to pay for a big increase in connectivity. The process seems simple enough, and could probably be done within a half an hour. Now that there is an external link why not build a Cantenna, hop in the car, and HeatMap the neighborhood!

Removable Router Antenna

antenna

[Mike] takes us through the process of adding  a removable high gain antenna to the WRTSL54GS in this article. The antenna that comes on this unit from the factory is a bit small and underpowered. After upgrading it using OpenWrt, an open source full featured router software package, he felt it needed a beefier antenna. So, he cracked it open. The new antenna can simply be soldered in place, where the old antenna was.

Gray Hoverman UHF Antenna

ant

With the impending digital switchover, many of you will find yourselves not only in need of a new converter box, but an antenna as well. Just like everything else, there are plans out there on how to build your own. [William] has gone through the effort of documenting his design and build of a very nicely made version. He used PVC for the frame and a wire mesh or chicken wire reflector. Good job [William]

UHF Power Harvesting

hdpowerharvesting

[Alanson Sample] and [Joshua R. Smith] have been experimenting with wireless power transfer for their sensing platform. Their microcontroller of choice is the MSP430, which we used on our e-paper clock. They chose it specifically for its ability to work with low voltages and they discus its specific behavior at different voltages. The first portion of their paper uses a UHF RFID reader to transmit to the sensor’s four stage charge pump. They added a supercap to provide enough power for 24 hours of logging while the node isn’t near a reader. For the second half of the paper, they use a UHF antenna designed for digital TV with the same circuit and pointed it at a television tower ~4.1km away. It had an open circuit voltage of 5.0V and 0.7V across an 8KOhm load, which works out to be 60uW of power. They connected this to the AAA battery terminals of the thermometer/hygrometer pictured above. It worked without issue. The thermometer’s draw on a lab power supply was 25uA at 1.5V.

It’s an interesting approach to powering devices. Do you have an application that needs something like this? For more on wireless power, checkout this earlier post on scratch building RFID tags.

[via DVICE]