On September 8, 2014 at 09:53, highfigh said...
I know they're shields and I know the top grid isn't really 'extra',
Glad to hear that. When you called them "tube covers" and "extra grid wire" it didn't seem like you knew.
but since noval tube sockets weren't being used at that time, I meant that it's extra WRT octal sockets.
It didn't even occur to me that those might be octal sockets. The chassis I've seen that looked like that had six pin sockets with no center pin and tubes with numbers like the 35 or 37; the rectifier would be the 80 with four pins. The pins connected to the filaments on those tubes were thicker than the rest, making it hard to put them in wrong, but not impossible. The center pin of the octal and loctal tubes could not be put in wrong.
I also know 'ground' is zero potential difference.
Well, no offense meant. When I write, I write for the person I'm commenting to as well as to the rest of the guys who might run across this. To some it's a novel idea that ground is a DC potential of zero, just as it doesn't occur to most us that DC is a signal with a frequency of zero Hertz. I added that comment to answer
their question "what do you mean by grounded or held at
some other DC potential? How is ground a DC potential?"
There's a further argument that could be brought up, that "potential" can't be zero because potential indicates the presence of a level of energy. But if you can have positive energy levels that are potentials, and negative energy levels that are potentials, it makes no sense to define potential as discontinuous, with the zero point
not being potential. And zero is a level.
I also figure you know all that stuff I wrote above about earlier tube pins, but some others might not know it. And there were no nonal tubes as large as the ones in the chassis you showed.
Magenta- early '80s? That would be the same time Sony had TV colors like mauve, taupe and teal.
Yup, early 80s. Maybe started in the late 70s.
