These tube specifications are interpretations of pages copied from a Russian language tube specification manual, sent to me by UR4LL, compared with specifications presented on various sites on the www. An excellent Russian-English Technical glossary was compiled by G4PMY which helps understand the Russian specifications sheets! I found agreement on most tubes (and validated my "reading" of the Russian data). I also found one or two instances where the data on the web was incorrect. Several web sites carry information about these tubes; those I found with the most data are Tube Data Sheets, DF6NA, PE1OGF, and Scientific Technical Centre NavigatoR. Additionally, to get me started, UR4LL provided english notes on the initial data sheets.