Transistors

[Terry]

"However, taking a typed data sheet for a much more modern valve shows a complete absence of Vb http://www.r-type.org/pdfs/eabc80.pdf"

Ist enclosed table, left hand column....

I see what you mean! I can't find the Mullard version on-line - although I suspect that it is identical to this http://frank.yueksel.org/sheets/010/e/EABC80.pdf  but what dominates the line is the initial 'Supply Voltage' and the later Vb is not so dominant as the bolder American B+ so, many (like me), I guess, would never notice it.

However, would a novice think that Vb and V+ are the same thing, especially as, unlike B+, I don't think I've ever seen the HT line marked as Vb on a circuit diagram?