Sdr spectrum analyzer. Even though it was pretty plain even with just your phone. Go into the room, close the metal door and your phone and wifi signals would plummet by 40-50db. You couldn't place a cell phone call from within the room.
Discussion
What frequencies did you check?
Just a curious hamradio operator. Kinda fascinated that those ingredients do fuck all
The server room was at a location that was our central hub, sending out from there to links in rural areas. We had a lot of 5ghz unlicensed stuff, and some licensed dragonwave stuff that was at ~16ghz if I remember correctly. The paint plus some metal shielding kept the room pretty clean of interference.
So you didn't look at any of the typical ham frequencies.
Where they having problems? I've worked on some high frequency backhaul before and I don't recall ever having the RF cause issues with other gear. Typically that stuff has directional antennas with pretty steep drop off outside of the path.
I thought it wasn't necessary either honestly 😂 The boss wanted it though.
It was on site at a 300m tower, in a leased room for our equipment. There was a lot of other things at that location too, terrestrial TV & Radio broadcast, other microwave links, cellular stuff as well, even some ham stuff I believe. The boss had 20 years experience though, and it was replicating the setup from our initial location which had a similar set of conditions. I'm sure he had his reasons.
sounds interesting for preventing EM side channels for computers processing sensitive data…
but for WiFi it could even be beneficial if it was also reflecting to some extent instead of fully absorbing, because it would make MIMO more effective
Possibly, but sometimes reflection isn't your friend. I remember having issues shooting 5ghz links between sheet metal buildings and having to turn the signal way down, or echoes started causing interference.