I think I read this in an anthology. Some guys start to order parts from mail catalog, super-transistors and other components that are really sent by aliens. I cannot really remember how it ended. Does anyone know the title?
Isn't that the plot of This Island Earth? That was serialised at first before it became a novel.
The protagonist is an engineer who orders parts from a catalog and receives unexpected components and instructions to build a mysterious device called an "interocitor".