Cathode Ray Tubes: invention, explanation and experiments

I wonder if we're seeing something... Is the beam moving in a loop? Are we seeing any noise somewhere? Maybe it's because of the power supplies? No. So it's not because of the deviation. It's coming in from another side. It could be these cables. No... Be careful, it's on. Yes, although it is close to zero volts. It is not the

cathode

. As long as I stay away from the

cathode

. Oh ho, that makes a big difference. AHA! I think you're focused, but there's something leaking into the electrodes. Alright, TubeTime magic fingers. Wow, it's detecting all the magic!

Oh, you know what? We don't have the mu shield around this thing. Good? This tube must be completely protected by something. Here we go. Yes, oh, and you can see well what's happening. There you go. Go faster! There we have it. Uh, give me a sine wave. There you go. It's the other one there. There we have it. Alright! Oh, we've finally made an oscilloscope! Oh! Ah! Can we see the shock wave or whatever? Yes, I can see the wave. Oh yeah, there you go, you can see he's still doing it. That seems like 60 hertz to me.

Yeah, it could just be that transformer here. Now we can solve it. We have our own oscilloscope, right? Good! So let's turn this off. how to make an oscilloscope with many HP equipment. There you go! So that's a little bit more than a full cycle. And we are at 30 Hertz. So yes, what we are seeing is 60 cycle interference. Okay, so we're looking at a transformer from somewhere. My bet is that it is this one. Then we would need to protect the tube. Yes, here is our new

invention

: the vertical oscilloscope! Ha ha! There's a lot of noise in there.

Yes, it has to be 60 Hertz. And that's a problem with

tubes

: you see all the defects. All defects are noticeable if the power supply is noisy. Everything happens through him. And if I set the frequency to a multiple of 60 Hertz, then we should be able to see a clean trace. Ah, very clever! By the way, this is why NTSC uses 60 frames or 60 fields per second. Let's do 60 hertz. Here we go. That's clean there. Oh, that's pretty good. Yeah! We are now very close to 60 Hz, and you can tell that the noise we are seeing is 60 Hz from somewhere.

Isn't it great? And Eric, while we were working on the other video, making nice exponential graphs, you turned on another tube. That's a small one. He's a tiny guy. Okay, well, this is good! Because I thought that tube was dead, because it had so much, it has a stain in the middle. It has a lot of burns. Yeah, if you look at the middle, right here, it has this huge line. Because   that's what I used to show. It is for the CV-89. But it is very good! And how much voltage do you need for that? Uh, this is 2000 volts right now.

In fact, we can reduce it to 1000 and experiment with a higher deviation factor. Ah, but then you see the burn. Yes, you can see the burning on the screen. We also tried our largest round tube, also from a Tek scope, but this one requires a 10kV post-throttle voltage, which we don't have yet. Without the rear acceleration activated, the place was too dark. So we will review it later. And for the grand finale, Eric brought his triple scope watch that he built from scratch a few years ago as an exercise: its own power supply, deflection circuitry, and software design.

You get it, we love CRTs. I hope you do too. See you in the next episode!