Working keyboard shielding

This is a sloppy video, but it worked well enough that I thought I'd post it until I make a better one:

https://youtu.be/yQgb_aBUyis

I used this: https://www.google.com/url?q=https%3A%2F%2Fwww.ebay.com%2Fitm%2FUS-Stock-0-5mm-x-100mm-x-1000mm-99-995-Pure-Iron-Foil-Fe-Thin-Sheet%2F372501495398%3Fhash%3Ditem56bad1be66%3Ag%3A0MoAAOSwBkRaDDwN%3Ark%3A3%3Apf%3A0&sa=D&sntz=1&usg=AFQjCNFVVmFnupDcagcEJn1JBHYdKt_oJQ

...connected to this:

Actually, plain steel and aluminum foil seem to work OK on that keyboard also. I'd had bad luck with both on other devices, so I didn't try them right away.

This one is also constructed in a way that makes it relatively easy to add foil or thin sheet metal to.

That's some fairly thick metal. Are you sure it fits inside?
I assume you're going to put it inside and punch holes in it for the keys, right?

The aluminum foil will fit, I think. I will test it soon. It does not require holes when used on this keyboard because the foil seems to be flexible enough. (It only needs to flex by half a millimeter.)

There may be something about the fields from this keyboard (a Chicony KB-2971) that makes them easier to block. I have not had this much success with mice or other keyboards. I ordered the USB version (KU-2971) to see if it is the same.

The iron foil would require 1mm of plastic to be removed from the gussets on the back of the key plate (easy with sandpaper, a special knife or a file).

This is the inside:



The ridges/gussets in the top half of the keyboard would need to be shaved down to make room for thick metal sheet. With the right tools that can be a 5 minute job.

Good news and bad news...

Good news: I'm typing this from the modified keyboard.

Bad news: For some reason the foil doesn't help as much when it's inside the keyboard. (This is true even with a layer of plastic foil insulation.)

It sounds slightly better at the high end of the range of frequencies that are audible on the AM radio, and my hands are less numb after using it, but I need to figure out how to improve it.