"neon bulbs" are actually gas discharge voltage suppressors. They go in hard conduction when the voltage at their terminal goes over their rated one. Most CRT devices use either "spark gaps" or gas discharge tubes on all electrodes to ground. The really cheap sets only have narrow slots on the neck board between electrodes and GND, these are "poor man's spark gaps".
btw, the "test lamp" wattage would be best not more than three times the rated wattage of the monitor :) I'd say between twice and three times the overall wattage of the thing under test is a good range.
That Hitachi is what I had for my first computer in high school, an Exidy Sorcerer, back in '77. Best I could afford -- until I eventually got a Kaypro 10 in college (gee, still 9" monochrome -- but it was green!)
"neon bulbs" are actually gas discharge voltage suppressors. They go in hard conduction when the voltage at their terminal goes over their rated one. Most CRT devices use either "spark gaps" or gas discharge tubes on all electrodes to ground. The really cheap sets only have narrow slots on the neck board between electrodes and GND, these are "poor man's spark gaps".
That makes sense.
Some analog attenuation analysis? Some conceptual crt confoundment?
Interesting inquisitive imagery inspection! A++
Hey Birt! Nice job! I so like old monitors! Unfortunately they are a true rare thing in this part of the world.
btw, the "test lamp" wattage would be best not more than three times the rated wattage of the monitor :) I'd say between twice and three times the overall wattage of the thing under test is a good range.
Excellent video and work! Thanks for sharing
Two Truely Tremendous Technical Teardowns!
🤓
Dood those worked awesome with Apple II’s.
That Hitachi is what I had for my first computer in high school, an Exidy Sorcerer, back in '77. Best I could afford -- until I eventually got a Kaypro 10 in college (gee, still 9" monochrome -- but it was green!)
I was impressed with the picture quality. It was much nicer than the Comrex.
Comrex is beautiful