Hallicrafters SX-99 Repair & Restore

From a channel Lumen includes in full: Tony (XrayTonyB), an audio and test-equipment repair technician, restores vintage receivers and amplifiers in long, methodical lessons on circuit operation, alignment and troubleshooting.

A 82-minute video from XrayTonyB's catalogue; the title names its topic.

Video by XrayTonyB, played through YouTube's embedded player.