I picked up this little (well its fairly big actually) vacuum tube radio from my local Goodwill for $11. I remember the person at checkout “keep your receipt in case it doesn’t work” they said.
“Oh I’m counting on it not working.”
The case has a nasty crack and a bit missing from the corner. As I’m writing this post (much later than the work and video was done!) I’m in the middle of fixing that all up using my 3d scanner, printer, and a little elbow grease. Stay tuned for that one.
I got it going, but with no volume to the audio at all. Bad output tube? No.
But here again. Rookie errors. There was a capacitor on the schematic that I didn’t replace. Why?
I literally couldn’t see the stupid thing because it was inside of a shielding coil that was itself wrapped in electrical tape. Out of sight, out of mind, I guess. Tore my hair out trying to figure that out, until I just counted the capacitors up and did the math. “Hey, there’s one missing? Where is it?”
Oh, there it is. Derp.
Replaced that and it just sprang to life. Of course. Moral of this story? Check your work. Sometimes things aren’t just obvious.
Stay tuned for the next video on this unit, so far its looking like it’ll turn out ok. Fingers crossed.