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Old 12-10-2018, 03:11 PM
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AlanInSitges AlanInSitges is offline
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Join Date: Nov 2017
Location: Sitges, Catalonia, Spain
Posts: 446
Nah, I didn't bother, the lady mailed me the same schematic for the 1077 that is floating around the web.

OK, another day, more head-scratching. I probably picked a tough place to start this hobby, but I'm in it now and hopefully I'll see it through to the end. I really don't understand the architecture of this thing. On a high level yes, but getting down into detail I'm confused. This goes to more general TV circuits and not just the 1077. Here's my understanding, which is clearly wrong, no need to be gentle:



The horizontal and vertical oscillators depend on boost voltage (vs B+) for their plates. The boost generally comes from discharging a capacitor (which I don't see in the 1077) off the damper tube, which conducts as the magnetic field in the flyback collapses after the horizontal output tube stops conducting at the end of each scan line. So...if the horizontal oscillator is not running, there is no pulse on the grid of the horizontal output tube, which does not conduct, which does not cause the magnetic field in the flyback to collapse, which does not cause the damper to charge the capacitor, which means there is no boost so how does the horizontal oscillator start with nothing on its plate? I can see the chicken but there seems to be no egg.

Someone please straighten me out!
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