IMHO neutral injection is probably illegal since it circumvents FCC Rules especially with the Commission's description as to how CC works. The intention is for the signal to be blocked by the first transformer the signal encounters.
No comments or rebuttals?
I am interested in your reference to the "Commission's description as to how CC works." Perhaps more details which lead to your conclusion would help.
Neil
From the FCC:
<h3 role="heading" aria-level="2">Carrier Current and Campus Radio Stations</h3>
Carrier Current stations and Campus Radio stations do not require a license to set up and operate. A carrier current station consists of an AM radio frequency signal on a frequency between 535 and 1705 kHz injected into a power line. The effective service range of a carrier current station is approximately 200 feet (61 meters) from the power line; however, a carrier current signal will not pass through a utility transformer. Campus Radio stations may be operated on the campuses of educational institutions provided that such operation is not within the service contour of any AM station on the same frequency, and the emission field strength complies with the limits in Section 15.221 on the campus and at the campus' perimeter.
Facts Aren't Rules
The statement "a carrier current signal will not pass through a utility transformer" is a technical fact but not a requirement of rule.