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Fun fact: this jet was designed to survive an EMP by using vacuum tubes, one of which was the 6C33C. This tube was a Russian military secret until a Foxbat def

Fun fact: this jet was designed to survive an EMP by using vacuum tubes, one of which was the 6C33C. This tube was a Russian military secret until a Foxbat defected to Japan, who then invited the USA to "inspect" (completely disassemble) the plane. That tube lives on today among HiFi enthusiasts. https://blog.thetubestore.com/emp-its-np-for-the-6c33c-b-tube/ https://blog.thetubestore.com/emp-its-np-for-the-6c33c-b-tub...

rob74 5y ago
I think the EMP resistance was more of a welcome side effect, the main reason for using tubes was probably that tubes were a proven technology, while transistors were still new for aeronautic applications in the late 1950s/early 1960s when the plane was designed.
- hwillis 5y ago
  Development started mid 1959, when transistor radios were already very widespread. It also used Nuvistors, which were only announced in 1959. Cars were being sold with transistor radios in 1955. Many planes worldwide at the time (eg cancelled BAC TSR-2) were using transistorized avionics, and for a cutting-edge jet tried-and-true is less of a priority than it would be in a strategic bomber or something. It seems like a very conscious choice to use only nuvistors and tubes in the whole system, particularly for such a powerful radar. They were much larger and needed much more cooling, which gets harder the faster you're going.
  - ben7799 5y ago
    Radar has high current/high voltage implications that may very well have favored tubes at that point. Not the same low power electronics. If the plane needed to have a high power radio transmitter tubes might have been superior at that time too. It was still pretty early in the history of the transistor and active radar and radio transmitters are very different than consumer radio receivers.
    - GekkePrutser 5y ago
      This is true, powerful radio transmitters (to the tune of tens of kilowatts) used tubes for their final amp in the 90s. Perhaps still do even.
  - wil421 5y ago
    They lacked the capacity to build transistors due to communism and scarcity for certain resources/skills. They relied on electronics from overseas. Since they had tons of vacuum tubes already they could build jets. It was a welcomed side effect it was emp resistant.
    - daniel-cussen 5y ago
      America relied on electronics overseas too. They kept strong-arming vacuum tubes from Czeckoslovakia during the Cold War, they couldn't make them anymore. It's one World.

rob74 5y ago

I think the EMP resistance was more of a welcome side effect, the main reason for using tubes was probably that tubes were a proven technology, while transistors were still new for aeronautic applications in the late 1950s/early 1960s when the plane was designed.

hwillis 5y ago
Development started mid 1959, when transistor radios were already very widespread. It also used Nuvistors, which were only announced in 1959. Cars were being sold with transistor radios in 1955. Many planes worldwide at the time (eg cancelled BAC TSR-2) were using transistorized avionics, and for a cutting-edge jet tried-and-true is less of a priority than it would be in a strategic bomber or something. It seems like a very conscious choice to use only nuvistors and tubes in the whole system, particularly for such a powerful radar. They were much larger and needed much more cooling, which gets harder the faster you're going.
- ben7799 5y ago
  Radar has high current/high voltage implications that may very well have favored tubes at that point. Not the same low power electronics. If the plane needed to have a high power radio transmitter tubes might have been superior at that time too. It was still pretty early in the history of the transistor and active radar and radio transmitters are very different than consumer radio receivers.
  - GekkePrutser 5y ago
    This is true, powerful radio transmitters (to the tune of tens of kilowatts) used tubes for their final amp in the 90s. Perhaps still do even.
- wil421 5y ago
  They lacked the capacity to build transistors due to communism and scarcity for certain resources/skills. They relied on electronics from overseas. Since they had tons of vacuum tubes already they could build jets. It was a welcomed side effect it was emp resistant.
  - daniel-cussen 5y ago
    America relied on electronics overseas too. They kept strong-arming vacuum tubes from Czeckoslovakia during the Cold War, they couldn't make them anymore. It's one World.