Mw ERP?

[Uncle Kaimbridge]

From “It Took Longer Than Expected But Bye, Bye Talk 1200” thread:

AM stations in the lower part of the band have much better groundwave than higher frequencies. 5kW on 610 is like having 15kW on 1200 or 50kW on 1580.

That brings up an interesting idea.
FM/TV has pure transmitter power (“TPO”) and ERP: E.g., WODS is a “50 kW” station, but has only a 8.7 kW TPO, as the 351m high antenna provides an effective radiated power of 50 kW.
Couldn’t an equivalent ERP be devised for MW, that takes into account frequency and soil conductivity?

 

[w9wi]

Absolutely, and I've seen it quoted from time to time. (they usually don't take conductivity into account, but they should!)

I suspect the reason it doesn't usually happen is because the ERP of most AM stations varies dramatically with azimuth around the antenna. Even at non-directional stations, the ground conductivity can vary pretty wildly.

 

[ThatGuyOnTheRadio]

From “It Took Longer Than Expected But Bye, Bye Talk 1200” thread:

AM stations in the lower part of the band have much better groundwave than higher frequencies. 5kW on 610 is like having 15kW on 1200 or 50kW on 1580.

That brings up an interesting idea.
FM/TV has pure transmitter power (“TPO”) and ERP: E.g., WODS is a “50 kW” station, but has only a 8.7 kW TPO, as the 351m high antenna provides an effective radiated power of 50 kW.
Couldn’t an equivalent ERP be devised for MW, that takes into account frequency and soil conductivity?

The height of the antenna doesn't establish the ERP. It is the gain of the antenna bays.