Location
he WebSDR is located in Maasbree JO31AI (QTH PH4RTM), intended as an alternative for HAMs having a high local man-made noise level.
The Maasbree location is quiet with on 20m a better than rural noise level. With now and then a weak local noise source.
Koos PA0KDF has done measurements with calibrated equipment and antennas: Measurement Methodology and Results of
Measurements of the Man-Made Noise Floor
on HF in The Netherlands