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Think about an average delay, half a second maybe? Now think how long you can delay a signal with a triode. Now how many of those add up to half a second.
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Education is what you're left with after you have forgotten what you have learned. -
BBD chips seem to have 2 transistors per stage (as far as I can see on the datasheets). So, a 512 stage tube-BBD should only need 1024 triodes, plus a few more for the signal buffering and mixing and some type of clock function. It should be possible with just over 500 tubes. Still pretty unrealistic, but at least several orders of magnitude less than 66000 tubes.Comment
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The transistors in a BBD are MOS devices specialized as switches. Tubes don't work that way; they don't form low(ish) value bidirectional resistors when turned on. This is one of the places where the analogy between tubes and FETs breaks down in a fundamental way.Originally posted by d95err View Post
But you have put your finger on the real issue - congrats! you're the first person to do that since I concocted this bit of hyperbole a few years ago. Using tubes requires using them for digital flipflops to implement the delay digitally, and that makes for 16 tubes per delay stage. If tubes did act more like FETs, you might cut this back to one or two tubes per stage, saving a lot of tubes. It's more realistic (for a completely unrealistic speculation!
) to figure a sample/hold amplifier circuit per delay stage. This design approach change might be only a few tubes per delay stage, so might save a significant fraction of the digital delay design - at the obvious cost of poorer performance.
Amazing!! Who would ever have guessed that someone who villified the evil rich people would begin happily accepting their millions in speaking fees!
Oh, wait! That sounds familiar, somehow.Comment
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I knew there had to be a catch...
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