WASHINGTON�Ground conductivity helps indicate AM propagation characteristics, with higher ground conductivity meaning stronger AM propagation. The FCC is now offering a printable, 43×69-inch map of the United States� estimated ground conductivity via a downloadable zip file.
The map shows that ground conductivity across the U.S. ranges from 0.5 to 30 millimhos (or millisiemens) per meter. The FCC also reports that the conductivity of seawater is 5,000 millimhos per meter.
The downloadable map comes in 48 portions that can be scanned and printed onto 8 1/2×14-inch paper. The FCC is also offering the conductivity data as text files and also includes data for the Chesapeake Bay and Puget Sound, which is not shown on the printable map.
For more information, click here.�