In this tool restoration I focus on a 900-Sterling Rectifier made by The Sterling MFG. Co. of Cleveland, Ohio. The rectifier was most likely used as a battery charger for radios and cars in the 1920s. From my research, I do no think this exact model is a common tool as the pricing suggests it was around 5% the cost of a Model T in 1922. I believe this is a vibratory reed half-wave rectifier, but I am not 100% sure. This technology was used before vacuum tube diodes became popular. The actually restoration was much more involved than I thought it would be and I was concerned that I would not be able to get this to work once back together. Electrical wiring is not my area of expertise, but a bunch of research helped. I was not able to find an exact patent, but this one was close: https://patents.google.com/patent/US1179515 I chose to replacing the nickel-plating on some of the brass parts, but not all. I had to remake some bakelite pieces, but was able to revive others in plastic restorer cream. I also chose not to do a clear coat on this tool as the original paint seemed to not be that glossy originally. I would have also liked to rewire the main coil, but I just do not feel comfortable yet tackling that. I really do want to have a try at rewinding an electric motor, but I don't want to practice on something so uncommon. I was VERY surprised that this worked after I wired it back together. It took me about 5 hours of wiring to make sure this was put back together in the exact right way. Hopefully I can pass this along to someone that can exactly explain how it works! These are advertisements from 1922: https://imgur.com/a/7L0uZb6 28:39 Nickel-plating solution Checking continuity: https://www.youtube.com/watch?v=eUzKAxZ9pJ8 I would like to thank Evapo-Rust for sponsoring this video. Wrenches are now for sale at www.handtoolrescue.com Help secure more tools for future videos (if you want): https://www.patreon.com/handtoolrescue Instagram: https://www.instagram.com/handtoolrescue Facebook Group - Share your restorations https://www.facebook.com/groups/handtoolrescue https://www.facebook.com/handtoolrescue/ Reddit - Share your restorations https://www.reddit.com/r/HandToolRescue/