wrote:
https://dl.dropboxusercontent.com/u/...070%20Caps.jpg

In a Kenwood receiver. It is steel, not aluminum.

What is its purpose ?

looks weird, like an afterthough.

Is there anything fastening the metal "shield" to the PCB below? Maybe
they had that board rattle apart of break loose with the large caps and
bridge rectifier attached to it. I'd almost expect the caps in something
of that age to be screwed down with a collar and have wire wrap terminals
or something weird like they did then.

There's quite a bit of stress on the parts in those big heavy receivers as
they get shipped across the world.

Heard from one guy that sent to the factory where they had audio gear
manufactured that the power transformers were all being screwed down
wrong, with the spring washer in the wrong place. He told the production
people that's not going to work, but they ignored that.

By the time the stuff made it to the US, every transformer busted free. It
all had to be reworked in the US. Whoops.