Archives of Ham Radio Magazine

List of Broadcast, Fixed Broadcast, Studio-Transmitter Links (Feeders), Remote Pickup & Relay stations 25 - 87.5 MHz.

Figure R3 of 47 CFR 73.190 of the Commission’s Rules contains a map of the estimated effective ground conductivity in the United States. This data is used to predict the propagation of AM signals across the United States. A higher ground conductivity indicates better AM propagation characteristics. The map shows that the ground conductivity in the U.S. ranges between 0.5 and 30 millimhos (or millisiemens) per meter. The conductivity of seawater is 5,000 millimhos per meter, resulting in the best propagation of AM signals.

Figure R3 of 47 CFR 73.190 of the Commission’s Rules contains a map of the estimated effective ground conductivity in the United States. This data is used to predict the propagation of AM signals across the United States. A higher ground conductivity indicates better AM propagation characteristics. The map shows that the ground conductivity in the U.S. ranges between 0.5 and 30 millimhos (or millisiemens) per meter. The conductivity of seawater is 5,000 millimhos per meter, resulting in the best propagation of AM signals.

An unscripted, spur of the moment talk touching a little on how Sporadic E works and how you can use 6m WSPR to find high MUF Sporadic E paths.

You have probably heard people talk about ionosphere virtual height. What is it and why is it important for HF propagation?