I love collecting books for a variety of reasons. Books give the mood of the time, futuristic concepts, the release of the latest and greatest. And of course needed technical information. I will post in the near future five unlikely surviving periodicals from 1936. For now here is a picture of three RCA receiving tube manuals that i use often in my restoration work. The book in the center of the picture (RC-21) is the one i use the most.
My pick of the day, very dry and for the bench RCA's RC-21 receiving tube manual.
As shown RC-14, RC-21 and RC-23