Published: May 19, 2018
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By: Joseph Erdy, Cal Poly San Luis Obispo
Hashtags: #Analog #AnalogCircuitDesign #Antique #Audio #Electronics #Problem #problemsolve #problemsolved #Problemsolving #problemsolvingskill #Repair #repairtech #tube #Tubes #vacuumtubeaudio #vacuumtubes #Vintage
I picked up an old PAC 954-G tube tester from a ham swap meet for $3. The previous owner couldn't speak on its condition. He had never powered it on. I assumed it was broken. Sure enough, when I brought it home I ascertained that despite receiving power the meter display wouldn't respond to inputs. I replace the rectifier tube and began a lengthy troubleshooting process. Most tube testers are fairly complicated electro-mechanical devices. Once they break, they are usually beyond salvage. I discovered that meter itself wasn't broken, which was a good sign. I then turned to a schematic I found and began to systematically run continuity tests, I tracked the issue back to three open resistors. When I replaced these the tester worked just like new. Old testers such as this one, when working, can fetch a pretty penny on eBay.