It's been some time since I last added a new post to this site but I've not been idle. One of this summers projects was the installation of a new 160 m ground system. In the process I made a series of very careful impedance and field intensity measurements using a vector network analyzer and a spectrum analyzer. I've written up this work in some detail and you can find it at Download 160_m_vertical_measurements.pdf . File size is about 290 kB.