AARONIA GPS LOGGER DF ANTENNA
(reprinted from EDN Network)
Kenneth Wyatt – August 24, 2015
As mobile communications devices proliferate, the chance for interference to these systems, as well as to television, broadcast radio, and other communication systems increases. One important aspect of EMC is tracking down these interfering signals.
Figure 1 – A typical radio communications tower on a hill top.
Aaronia has developed a clever addition to their line of antennas called the GPS Logger. This accessory includes a GPS for location and elevation, a compass, and a 3D accelerometer, which keeps track of tilt and roll. In the case of the review product, the antenna is the HyperLOG 7060 (700 MHz to 6 GHz) log-periodic reviewed earlier, but with an attached 20 dB gain broadband preamp. Their small table top tripod is used as a handle for pointing the antenna and determining the direction of the interfering source.
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Figure 2 – The Aaronia GPS Logger mounted to a HyperLOG 7060 log-periodic antenna.
The GPS Logger is attached to the antenna itself, so that as you are locating the source of interference, the information is recorded on Google Map of location and compass heading. In addition, a running log of information stored on your laptop in case you’d like to post-process the data.
The GPS Logger is charged using a standard “wall wart” power supply. A small push-on / push-off switch activates it. The compass requires and initial “figure of eight” routine for calibrate (similar to what is performed on most smart phones). In normal operation, the antenna port is connected to your spectrum analyzer or EMI receiver, while the DataLogger is connected via USB to your laptop. Aaronia supplies the data logging software that runs on a PC.
Figure 3 – The logging software keeps track of your position and all the data is recorded in real time onto the PC.
By noting the signal strength and direction of the interference, it’s possible to zero in on the interfering location fairly quickly. Unfortunately, there’s no way currently to draw a directional line on the map in order to triangulate the source. Hopefully, this would become an added feature in future versions of the software. For now, you’ll need to keep track of the signal strength and compass bearing manually, or analyze the logged data later, in order to determine the source location.
Aaronia’s HyperLOG 7060 is the perfect antenna for most mobile telephone and wireless systems. The addition of a GPS and compass is a unique and useful addition. I’m looking forward to a more refined software application, however.
