One of the earlier technically oriented but popular radio magazines; by the late 1920's it had changed to focus on the trade. By 1935 if served the high-end experimenter community, especially in amateur radio (ham) communities. 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