[old_tv_nut]

Originally Posted by Rinehart

... The mosaic plate would then be charged up, and would retain its charge until it was scanned by the electron beam. At the bottom of the scan, the synch pulse would cause the next flash, which would charge up the mosaic again, which would be discharged during the next scan. In the meanwhile, the film would advance to the next frame, and the process would be repeated. And so, one frame of film would translate to two fields of interlaced video, because the interlacing would be accomplished by the iconoscope.

[Exactly]

Given all this, how would it be possible to lose interlacing?

[As you surmise, interlace will be OK]

As I said, I hope not to have irritated you too much,

[Not at all - I like to get these things straight in my own mind, and the best way is trying to explain them.]

but I really want to nail these things down before writing the book. Sloppy research and sloppy writing are an insult to the millions and billions of people who will plunk down their hard-earned cash for it.
Once again, thanks for taking the time.

Attached are the relevant pages from Fink, Television Engineering, 2nd ed., which show the 24 fps case. It should be easy to see that the 30 fps case works too.