Attenuation-comparison in the anechoic chamber (v3160vo.dat) and on concrete ground (v216216.dat) at vertical polarisation. The graph v216216.dat is very close to the attenuationmeasured under freespace conditions. Around 80 MHz the chamber attenuation is approx.3.2 dB higher than the free-space attenuation, using the same geometry setup and the same antennas