Article first posted earlier http://www.freerepublic.com/focus/f-news/1343320/posts
ART13 had some sort of auto-tuning of finals via phase detector circuitry I believe - detector outputs drive a servo etc, I'm not very familiar with them I'm afraid.
I forgot, you had to tune the finals of those radios to match the impedance of the output tubes to that of the antenna. Collins must have figured out how to do this automatically. Not bad (for 1945).
Thanks for the link.
(steely)