Vacuum Tube Curves in 3D

The Plate voltage curves and the Average Transfer Characteristics curves are simply two different views of the same data. This data from either curve has enough information (Plate V, Plate mA, and -Vg) to plot in 3D. Using my 3D program I import this data and show the 12AX7 tube curve data in 3D.
I also show what distortion looks line in 3D using the Dynamic Loadline (ellipse) that I have described in my video series on Dynamic Loadline calculations.
Original Work, Copyright 2021 James D. Whiteside, II all rights reserved, For consideration only, no reproduction without prior permission.

[@mangist]

This was very interesting and informative. I've never seen this way of looking at tube curves before, and provides much more info than the simple 2D datasheets do.

[@dancoe4489]

Awesome, thank you 😁

[@Dave_____]

Thanks for the video. Very helpful. Is the plotting software you use (made) available?

[@deepblueharp]

I am still working on the plotting software. It needs more development before I offer it. I'd like to add some more control to the axis formatting at a minimum. I also want to add a TCP interface so that data can be sent to it interactively from other applications (mine or others). It will late Fall before I can make a first offering of it on my website.

[@Dave_____]

@@deepblueharp Hello. I hope things are going well for you. I wanted to follow up on the availability of your plotting software. Thanks

[@deepblueharp]

@@Dave_____ Please send me an email. It is on my channel. Then we can discuss this a bit more. Thanks!

[@ShredEngineerPhD]

Awesome!

[@deepblueharp]

Thanks!

[@jimhenderson2308]

Great video. It would be great to build a physics based model of the vacuum tube of interest and then interrogate the model in the time domain to generate predicted behaviors from which these steady state performance curves are derived. I’ve been working on a virtual test bench to do just that. This virtual test bench would cycle an operating variable (plate voltage in this case) thru a range of values while holding another operating variable (grid voltage) at a constant value (aka incremented boundary condition). The next cycle would repeat the same way but with a new constant value for the boundary condition. In effect the interrogation is automated and the a plot of a family of predicted performance curves can be made. Doing this would test the validity of the physics based model by comparing prediction for performance curves against performance curves from measurement. The physics based model doesn’t even have to be in the same physical domain as there could a hydraulic equivalent of a vacuum tube. This “model” would be used to enforce the thermionic effects of a vacuum diode in a model of an electrical continuity scheme consisting of capacitors and inductors and resistors. Once the model accurately predicts the thermionic effects for a simple diode then the control grid effects could be added to modulate the current as a result of the thermionic emission effects.

[@deepblueharp]

A physics based model would be a keen approach. Currently, I have developed a heat transfer model to calculate warm up time, operational steady state and I am now working on the thermionic emmission model.