I recently bought a Accurate Instrument Tube Tester Model 157 ($22 auction). It has operating instructions. I scanned them and made a pdf. If you have one of these tube testers you really can't get accurate test information without the manual. So I'd like to share it if anyone needs it. Here is the link for the Model 157 manual and the June 68 Supplement Chart. Accurate Instrument Tube Tester Model 157 Manual.pdf Here is the link if you already have the manual but only need the June 68 Supplement Chart. Accurate Instrument Model 157 Supplement Chart June 68.pdf This link is for a Tube Substitution Guide I got along with the tester. Tube Substitution Guide.pdf And while I'm at it here's a manual for Schumacher E-Z MIG and 105 Turbo MIG FLUX WIRE FEED WELDERS MODELS 90775 90778 90779. Schumacher E-Z MIG and 105 Turbo MIG FLUX WIRE FEED WELDERS MODELS 90775 90778 90779 MANUAL.pdf It's not available from Schumacher anymore.