Making Electronic Tubes
| Field | Electronic |
| Went Obsolete | 1975 |
| Made Obsolete By | Semiconductors |
| Knowledge Assumed | Spot welding, glass working, electronics |
| When useful | After civilization-destroying phenomenon; making semiconductors require major infrastructure, just to purify silicon for example, audiophile applications, guitar amplifiers, high-power transmitters |
Electron tubes were phased out of the last American televisions in 1975, excluding the GE portacolo; they lingered in high-voltage circuits. Most Hi-FI gear shedded them in the mid to late 1960s. Transmitters used them until recently, but semiconductor solutions have largely displaced valves. While Western companies stopped making tubes in the 1970s and 1980s, Soviet countries mantained production out of nuclear fears. Today, these factories make valves for high-market audio gear and upscale guitar amplifiers; needed for the bizarre renaissance that started in the 1980s.