Re- low power AM
From a
technical viewpoint-
If several frequencies (with adjacent channel protection to full-power stations provided) are allocated to low power AM service, that would be fine. The outcome may not be as hoped for by the proponents because of interference.
Unlike FM or digital (within reason), receiver detection of amplitude modulation does not reduce on-channel interference. In this context, defining interference as undesired signal with less signal strength than the desired signal, at the receiver location. AM receivers do not benefit from the cocktail party effect.
en.wikipedia.org
Because of skywave propagation on lower frequencies used by AM radio, at night just 20 watts of power from one station can significantly reduce interference-free coverage of a co-channel station that is protected to its 0.1 mV/meter contour.
It may seem crazy a mere 15 watts could cause interference, but that power can exceed prescribed desired to undesired signal ratio at locations within the protected contour of another station hundreds of miles away.
Ignoring marketplace aspects, from the
technical viewpoint, engineers can determine most efficient use of radio spectrum for a given definition of service. On AM this could be 2 mV/meter ground wave daytime, and 0.5 mV/meter nighttime. Or whatever is decided. Remember skywave propagation coverage area is
defined by probability. And skywave coverage at a given probability may not be a contour, but an area with a beginning and end.
Thus there is plenty to deliberate.
My opinion-
At a given receiver location, AM analog needs sufficient signal level to override incoming interference from other stations. Increasing station power with no corresponding reduction in number of stations is
mutually assured destruction.
I don't think any AM licensee that is on the air and making a go of it should have their license rescinded for the "greater good".
I do think the FCC should continue to permit the marketplace to do things that reduce interference, provided
a community continues to receive signal level defined as local service.
btw- Important to distinguish between
distant skywave service area, and incoming skywave reducing
local nighttime interference-free area. Advantage of the current rules is Class A stations are relatively free from background interference in their audio at lower ground wave service contours.
A current proposal is a bit disingenuous because it is more than "nighttime only coverage hundreds of miles away", it is also how clean a station sounds at night in the outer areas of the local community.