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#1
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Hank wrote:
DeForest's misunderstanding of the principles of the Edison effect and the Fleming valve seems to have been pretty basic. His first attempts to control current flow were "grids" mounted on the outside of the glass envelope. And he always seemed to think that what he was controlling was ionized gas conduction, not electrons emitted from a cathode element. Likely some of what he was controlling _was_ ionized gas conduction. This isn't a good thing from the standpoint of getting low distortion but if you want a high mu and don't care about reliability or repeatability I can see it. There were tons of texts written around 1920 that had some pretty strange theories about what tubes did inside. As I recall, the first really good text on radio circuits I encountered was Mary Texanna Loomis's text from the late 20's. I learned EE basics from her text, Ghirardi's "Radio Physics Course" from 1932, and Terman's 1937 "Radio Engineering." One text that baffled me was Zworykin/Morton "Television," which I got as a present at the end of WWII. No wonder--the physics were much too advanced for me to understand. Looking back some years later, I think the best text on vacuum tube physics was Spangenberg's "Vacuum Tubes." It wasn't published until the dawn of the transistor era, so never got the play that Terman and some of the others did. What about Seely? That's what we used in my freshman EE class and it seemed pretty good. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#2
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On 03/30/2016 09:46 PM, Hank wrote:
There were tons of texts written around 1920 that had some pretty strange theories about what tubes did inside. As I recall, the first really good text on radio circuits I encountered was Mary Texanna Loomis's text from the late 20's. I learned EE basics from her text, Ghirardi's "Radio Physics Course" from 1932, and Terman's 1937 "Radio Engineering." One text that baffled me was Zworykin/Morton "Television," which I got as a present at the end of WWII. No wonder--the physics were much too advanced for me to understand. Looking back some years later, I think the best text on vacuum tube physics was Spangenberg's "Vacuum Tubes." It wasn't published until the dawn of the transistor era, so never got the play that Terman and some of the others did. Hank As I am reading more of de Forest's book I am now at the point where he finally realized the highest vacuum possible was needed, |
#3
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Never thought to check there first:
De Forest ruefully noted that under these conditions the only successful "wireless" communication was done by visual semaphore "wig-wag" flags. |
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