This twenty-four-page booklet from RCA in 1929 is a combination vacuum tube catalog and U.S. radio station directory. Two versions are available for download: First is a 9.2-megabyte high-resolution PDF, while the second is a 3.4-megabyte low-resolution PDF. A child’s pencil scribbles are seen on a few pages. This booklet was provided through the courtesy of Michael Callaghan.
Here are sample pages 7 and 8.