On Thursday, March 9, 2017 at 4:51:22 AM UTC-5, wrote:
"Having a plate connection on top of a tube instead helps a lot. "

It sure did with HOPs (LOPT for you all across the pond)

But IIRC in the beginning they used that top connector for the grid. Seems that later they figured out a better way.

LOL! I remember when I was just getting started in TV repair and my dad had a 40s radio in the shop for repair. In horror, I saw him put his finger on the "plate" cap of the IF tubes as a poor man's signal tracer. Of course, my first experience with a true plate cap was my finger on a horizontal output tube..