I don't think this was really a big deal in the story, just some on-going issue the protagonist was dealing with while carrying on with whatever the major plot was. It stuck in my head for some reason. I think I read this before 1970. It could have been a fix-up novel from a series of short stories. It could even be something I otherwise remember well but this part of the plot has become disconnected from the rest in my head.
The protagonist is an interstellar agent of some sort, working out in the galactic boonies. Some gizmo he depends on has been broken or lost. He has sufficient technical knowledge to describe how to build one, but the tech level in the region where he is currently stranded cannot reproduce it in a useful form. The gizmo (ansible? navigation tool? life-support aid?) was originally something he could easily carry around, but the first built-to-order replacement he contracts for is room-size. He tries again, maybe more than once, maybe switching planets, and eventually gets someone to make him a just-barely-portable replacement that is sufficient to get him back to more high-tech parts of the galaxy.