[dredmorbius]

Quoting the FCC link above:

"Carrier Current stations and Campus Radio stations do not require a license to set up and operate."

(Emphasis added.)

<https://www.fcc.gov/media/radio/low-power-radio-general-info...>

[solomonb]

Interesting! The rules for AM carrier current appear to be more similar to the FM rules, that is they are based on field strength readings that result in a roughly 200ft range.

There is probably a bunch of subtlety about where you measure from as your antenna could be quite large.