If you'll all indulge me, I have one more post for this thread. And I cannot fathom why I did not see this sooner.
Back when I first posted my calculated log-log plot, I asked the question about what was to be learned from the parallel tube characteristics when plotted against log-log scales. The answer is that all vacuum tube rectifiers operate in a space charge limited state of operation and obey the Child-Langmuir Law (more commonly called Child's Law). The consequence is that all vacuum tube rectifiers follow an I=k*V^(3/2) power law and all exponential power law relations are straight lines on log-log plots. Duh!
The important part of this is that ANY vacuum tube power rectifier V-I characteristic can be plotted from one point on the published I-V characteristic. I was doing it the hard way. (Imagine me pouring over data sheets and reading hundreds of numbers off of plots.
The process is actually simple. First take a single I-V data pair off the published characteristic (call these number Ir and Vr). From this generate a tube dependent constant (k) given by the following relation k=Ir/(Vr^1.5). Then the peak voltage drop at any given peak current for that tube is simply V=(I/k)^(1/1.5). When I checked the results given this way against the numbers I had read off the published plots, the errors were on the order of +/- 1%. This Actually Works!
Here are my latest plots comparing all the common rectifiers I could find. These are all full wave rectifiers except the 35W4 which is shown with a dotted line.
Tube Drop 1.png
Tube Drop 2.png
Is this useful to anyone?