I just finished the page for Seco 78 tube tester. Now, all my three testers, I177, Eico 635, and Seco 78, have their tube testing data and instructions available on web pages. Although I have reviewed all data, I'm not sure if they are all OK.
So use it at your own risk.
Page is available under 'Tube/Valve' - 'Tube Testers' - 'SECO 78' left menu, at the main home page.
Click here to check it out.