Thread by @mattblaze

Re-upping this: Testing Phone-Size Faraday Bags.
mattblaze.org/blog/faraday

You probably don’t need one, but if you do, here you are. And I think some may find the test process interesting.

How do you know I’m not shilling for one of the commercial vendors?

You don’t.

But I show my work, and you can do similar tests if you want (that’s the point of the writeup).

I’m fortunate in that I have some high quality test gear, but that wasn’t essential to being able to do this. You could get close to this level of accuracy with cheaper, hobbyist-grade gear if you understand what you’re trying to measure and what can confound the measurements.

Normally, tests like this are done in much more elaborate (and expensive) specialized lab setups than what I used. I wrote this up because I love reading other people’s experiences carefully investigating things like this with sub-national-lab resources.

If I had a lot more money, time, and space, I’d build a walk-in RF anechoic chamber (which is the right tool for this sort of testing). But that’s well over 10dB more formidable and expensive* than what I’ve got here.

* using the power ratio dB form, because money is power.

If it weren’t for the, you know, global plague, I’d planned to bring this to Shmoocon and let people measure things. Sigh.

Next year for sure!

Over the last week, I’ve been told I don’t understand decibels, that I should have used a tracking generator (why didn’t I? Think about the test setup!), and that I’m hiding the truth about aluminum foil.

Fortunately, I’m not stopping you from doing your own measurements.