The name of this site is OneTubeRadio, so it’s only natural that the logo should show a one tube radio.

The schematic diagram above was taken from Audel’s Radiomans Guide by Edwin P. Anderson, which was published in 1945. It is a very basic one-tube regenerative receiver. The book is out of copyright, and it’s one of many available at tubebooks.org, a repository of old radio and electronics books that are now in the public domain.  I have more such books linked on my old radio books page.  In addition to the ones at tubebooks.org, there are many available at Google Books and Amazon.