More on Soil Meaurements

It is extremely easy to take soil electrical data using the RigExpert by running a frequency sweep. This sweep is saved on the meter and then transferred to the PC and exported as an CSV file. This file contains impedance measurements across the sweep range. Add the formula to convert to conductivity and Er and you get the following graph:

This data was calculated with a Co = 8 pF adjusted after making a few more measurements. The average values per band are as follows:

The values above can be compared to those given as standard values in EZNEC. I further compared the gain results when using a 40m 1/4 Wave vertical with four ground mounted radials as follows:

In this case, the model has a 2.27dB difference in measured gain between the average soil case and the measured reading. In practice, using the “Very Good” values will likely be close enough for modeling work here at the QTH.