I often get asked as to what books a boat anchor/military radio collector should have on his shelf. I highly recommend "Tube Lore" by Ludwell Sibley. I wrote a review for CQ magazine several years ago and managed to save a scan of the pages. Unfortunately the manual has been sold out but sometimes is listed in ePay etc. The Tube Collectors Association can be found at:

                                          http://www.tubecollectors.org/

                      k4che