Radio

One of the earlier technically oriented but popular radio magazines, by the late 1920's it had changed to focus on the trade. After World War Two it became ... AUDIO ... and served the high-end audio enthusiast until the late part of the century.

If you like old radio, you will like the e-book reprint of the 1922 Sears, Roebuck Electrical Goods and Radio Apparatus Catalog. Here's a writeup about it, with pictures. It's $2.99, free of DRM, and with all the pages rendered as images you can enlarge to see detail, and even print out. It's $2.99! Follow the link.