Sources and sinks are ecological concepts that can be applied to placing artifacts. A source is a place where an organism breeds enough to not only replace its numbers but also spread elsewhere. Sinks are places where an organism can not breed fast enough to replace its numbers, and thus relies on immigration.
For artifacts, there are more or less four places where they are produced. Functional factories, mines, plane shift portals and aliens. Mines are those places where artifacts are dug up from landfills or buried ruins. The artifacts in them are of lesser quality than new but they were also protected from the elements and should be in better shape than devices that have been used since the cataclysm.
Other than these rare places, the world is one giant sink. Everyone wants power cells, weapons and other artifacts and fight over them. Many artifacts are broken by this fighting, a misunderstanding of their use and of course there is normal wear and tear from use (and decay for those yet to be found). So that means artifacts will be of three different distributions.
The first are those clustered in the hands of the powerful. They tend to be near or part of the source. Tiny empires can have their own primitive factories like the one in Gamma World's Overlord of Bonparr. These artifacts may not be the best but at least they are functional and usually powered.
The second are those spread through out a populated area, usually a city or cluster of towns. People buy or steal them from each other and the source. People from outside can enter such an area and join in the artifact exchange system, though they will be seen as outsiders and not to be trusted (ie to be price gouged or watched) in most places.
The third are those little dots that cover the map. Consider how many ruins there will be after the cataclysm. Billions of homes (including apartments), millions of industrial and commerical locations spread over land, sea and air. There are so many that scavenging will be easy as long as the radiation levels are low and the monsters are few, at least for the first few generations. Ruined buildings should be the number one encounter in the wastes, possibly only second to mutant plants. In a thousand years, if any Ancient artifacts still function, there still will be places where one can dig down and find them. Heck, military grade artifacts might be found just about anywhere between places where soldiers fell and where home owners hacked their 3D printers to make defensive gear.
Another source of those dots are time capsules. People wanted to make sure their favorite idea, technology, piece of art, money, etc. survived the cataclysm and thus buried such. There are three major types of time capsules found in the wastes. There are sealed containers, usually containing a vaccuum as well as the artifacts, though some have nitrogen gas or even poisonous to kill thieves. The second embeds the artifacts in a block of plastic or glass. Just break the shell and the artifacts are yours. The last are also blocks but are made of exotic matter. They can not be broken, only vaporized with the correct solvent. Finding the required solvent for a specific capsule can be a quest in of itself. Time capsules can be found just about anywhere, even in the lairs of unintelligent monsters that took a shine to their appearance.
What all this means is the ML can put artifacts all over the place, but those in the best shape are going to be limited in power and/or in location. Junk, piles and piles of junk will be the rule for artifacts in the wastes. Just look at the photos of the destruction from Sandy, Katrina and the two recent tsunami (Japan and Indian Ocean) to see what the wastes will look like, just imagine a coating of green (or other plant color) on top of it.
