Another RCA CT-100 discovery B8001599

[dtvmcdonald]

Originally Posted by old_tv_nut

The CT100 DC restorer discharge path is 1M ohm, and the charge path looks like about 10K ohm, which appears to be 99% DC restored to me.
I stand ready to be corrected if someone can detail how this circuit could produce only 85% restoration.

I'm actually not quite sure. I thought about it a lot and never decided.
What I report is what I measured with a 32 megohm resistive (and proper compensation capacitor) scope probe.

I think is some sort of combination of the presence of sync pulses and setup
in the signal and the presence of added blanking pulses.

But what I AM sure about, Consumer Reports notwithstanding, is that
with the brightness level of early CRTs, consumers did and should have complained about not seeing dark pictures well with 100% restoration.

Same thing applies to photos: I print some of my photos in a way designed
to be viewed in direct full sunlight. People ooooh and aaaaah about these when displayed properly ... but complain if viewed at "official museum light levels". That needs different (dodge and burn) processing. Such processing is clearly visible in sports programming in modern TV. Look at white parts of uniforms in direct sunlight.