In late June, the DARC EMC consultant Klaus Eichel (DL6SES) visited OV Landshut to install an ENAMS (Electrical Noise Area Monitoring System) station at U08. This station is part of a larger effort across Germany to monitor and track electrical noise in both rural and urban areas.
Finding the right location for the ENAMS station was crucial. After some searching, a rural site was selected that met the "rural" criteria and had a stable DSL connection. The site was meticulously prepared—80 meters of power and Ethernet cables were buried, and an outdoor cabinet was installed to house the ENAMS electronics. Additionally, 25 meters of antenna cable were protected against potential damage by being encased in a pressure- and cut-resistant conduit. This setup ensures the antenna is shielded from nearby interference sources, with the nearest inhabited building about 100 meters away.
The antenna location "in the countryside
However, even in this remote location, measurements revealed that the lower amateur radio bands (160m, 80m, and 40m) were not entirely free from interference. The source of this interference is currently under investigation and may be located several kilometers away. On the positive side, for bands above 10 MHz the noise floor is mostly within acceptable limits, with only a few outliers.
Noise floor related to ITU "rural" (0dB line) 10.11.2020
Noise floor related to ITU "rural" (0dB line) 11.11.2020
At the heart of the ENAMS system is the Red Pitaya digitizer, a versatile and powerful tool that drives the entire noise monitoring setup. The Red Pitaya unit is connected to the local internet router, automatically transmitting data to a central server in Baunatal without the need for user configuration. This data is then evaluated, and the results are used to create visual representations of noise levels, helping to map the electrical noise landscape across Germany.
ENAMS electronics in the control cabinet
The ENAMS station at U08 is a significant step in monitoring electrical noise in rural areas. While there are still challenges, like identifying and mitigating local interference, this project is helping us to understand and reduce electrical noise. And as the network of ENAMS stations grows, so too does our knowledge of how to better manage such noise across Germany.
If you’re curious about the technical details of how Red Pitaya supports ENAMS, check out our previous blog post, where we take an in-depth look at how the system works, from antenna design to data processing.