I have re-labelled the electrodes in my pentode models.

Instead of cathode, grid, screen and anode, I now have cathode,
grid, anode and drain, respectively.

All that stuff about making a pentode by inserting a screen between
anode and grid was getting on my nerves, and clouding the issues.
The extra electrode is beyond, not between.

I was told, in order to understand the triode, to look at the
development of the tetrode. Spot the conundrums!

So, the triode must have been produced for years before anyone
understood it. Same could be true of the tetrode. So why should I
entertain the madcap "scientists" of the time? How the engineers
must have laughed!

cheers, Ian