Vintage info from the days of vacuum tubes

Herein you will find a collection of vintage engineering texts, vacuum tube datasheets, and other obsolete information, presented free of charge and without annoying advertisements.

For other DIY-audio-related information, please visit

Many files on this site, especially scanned documentation, are in Adobe Acrobat (PDF) format.  I recommend that if you don't already have it you download the latest version of Adobe reader.  Some files have compressed images that may not work correctly with older versions of Acrobat reader.


If you have questions, or would like to donate material to this site, please feel free to e-mail me at:  

Please, if you send e-mail, make sure that there is a logical "subject", or your mail will get dumped along with all the junk mail (spam).  If I don't respond within a few days, try again, just in case I missed your message.  I try and return everybody's mail within a week, though I travel quite a lot for work and find I get very behind at times.  Please be patient...

NEW 8/24/21- "Fundamental Radio Experiments"


Russian Tube books - Posted a number of Russian-language tube books and manuals

Technical books -  Full image scans of old technical books related to tube audio, radio, and pre-silicon electrical engineering and technology

Vintage audio info and articles - Everything but books: magazine articles, schematics, catalogs, brochures...

McIntosh service data - Schematics and other service data for classic McIntosh products

Transformer data and schematics from Tango, UTC, Thordarson, Acrosound, Chicago...

Tube Data, including some data from RCA, Western Electric, GE, Tung-Sol, etc.

RCA HB-3 Tube Data Manual

1951 and 1959 Sylvania tube manual