The Electron Tube Catalog is a software application designed to house over 4000 records of various electron tubes. It has a searchable database that includes the base pin-out and parameters of the components. The software also features a CV/M2/VT type substitution searcher and a tube characteristic drawer.

The database contains detailed information about the base pin-out and important parameters of the components, making it easier for users to identify and work with them. Additionally, users can also make use of the substituted searcher and tube characteristic drawer tool, which are both incredibly handy features.
Another great feature of the electron tube catalog is that it receives monthly updates, ensuring that users are always accessing the most up-to-date information. If you're interested in trying the application, you can download and install Tubes2 Open edition from the homepage completely free of charge. The best part is that you can modify and redistribute this version under GNU GPL 3.0 or later for your convenience.
Finally, there is a yearly database update as well. All in all, the electron tube catalog is an incredibly useful software for people who work with electron tubes and components regularly. With its extensive database, search features, and regular updates, it can make the entire process much simpler and more efficient.
Version 2.2: Type substitution searcher and characteristic drawer included.