Bob-O-Scope, Part 1

Labguy starts a new project today. based upon a neat 3cm or 1 and 1/4 inch cathode ray tube, the foundation of a very compact and simple X, Y and Z display is constructed. This tube is the D3/130GH made by Brimar in January of 1978. We deep dive the DC circuits required to make the tube operate at its most basic level. Comparison is made between this tube and it's equivalent competitor, the Cossor 1CP1 also known as the Philips DG3-91. Sit back and enjoy a layman's lesson in simple electrostatic CRT circuit design. Do you have an electrostatic CRT in the one to three inch class? Let us know in the comments if you can make your tube work with what you learn here.
WARNING. These projects operate at moderately high voltages and medium currents. Consider your safety at all times and work with care. If in doubt, don't risk it.
Most of all, enjoy the project. If you like the video, you know what to do. Leave a comment if you are so inclined. have a great day!
~Labguy~

[@cocusar]

pretty cool little oscope!

[@MrSlehofer]

Awesome to see you back in action!

[@W1RMD]

Cool project! I like the way you slowly explain everything without going too slow or assuming we already know..

[@videolabguy]

Thank you, Ryan. My goal is to spread the, "golly, gee whiz!", far and wide. I like when someone is delighted by learning about a topic they have never encountered. Discovery can be a great source of pleasure and the viewer is a little smarter afterward too.

[@KanalFrump]

nice project. appreciated the schematic breakdown.

[@Gin-toki]

Thanks for this thorough and easy to follow explanation.

[@discoordination]

Thanks a lot!

[@TeslaTales59]

That's a super cool project using and old CRT! Good to have you back sir.

[@UpLateGeek]

That's a very cute CRT! I've seen Fran's video on the Nimo tube, but I never knew they made a full CRT that small. It's also interesting to see how "simple" it is to get it to light up and manually control the spot, at least in terms of how few basic components are required (I'm sure it took more than a little head scratching and scribbles on a notebook page). I've got an ancient vacuum tube powered CRT oscilloscope, I'm guessing from the 60s. I've taken a peek inside only to be surprised at how few components are in there, so I'll be following this project with interest.

[@ct92404]

Just curious, does your oscilloscope work? Or are you planning to restore it? You should post a video about it sometime. I love antique electronics, especially ones with vacuum tubes!

[@UpLateGeek]

@@ct92404 I haven't tried using it in more than a decade, but it worked back then. The beam was a bit unstable, so it probably did need some work. I'm guessing it might need more work now. It's currently buried somewhere in my storage shelving, behind many boxes, and I've got a lot of other projects on my desk at the moment, so unfortunately I'm not likely to get to it any time soon.

[@039dalekmoore2007]

Always interesting to watch and learn from a master ,i am funny enough on to another CRT monitor my self any case watching with interest .

[@mido-gq3xe]

Very interesting project, i like it

[@RubberChickenFilms]

"Cathode Bob" doesn't quite have the same zing as "Cathode Ray," so I'm glad Bob still gets something.

[@scottgfx]

There was a comedy duo called Bob and Ray, so I think it works! :)

[@taecheon]

Happy to see you return! The X,Y CRT is right down my alley. Are your schematics available anywhere. I must adapt for my 2AP1s and my poor eyes....

[@fredrik7574]

Great project ! I have a couple of old CRT's and will try some of your ideas. I have a very serious question though; How come you say (and draw) the current flows from minus to plus in the load? The electrons certainly do, but the current (I) does, by definition, flow from positive to negative through a load.

[@videolabguy]

The simple answer is that is how I was taught current flow in the 1970s. It also parallels with the electron flow in the tube.

[@ct92404]

Hi Richard, do you still do any 3d printing for your projects? I was working on a small model and I was wondering if you could look at it and see if you think it would actually work with a 3d printer. I've been researching local history and I wanted to make a model of a trolley or streetcar that ran where I live. Can I email you the STL or OBJ file?

[@videolabguy]

I have not had enough time to do any printing. I am no expert on this topic either. I'd like to help. but, it would be untruthful for me to offer help at this time.

[@ct92404]

@@videolabguy Ok, I understand. Thank you for the reply!