This works great. (wondering the first thing I was going to build with these things.)
I made sure that all WiFi, Bluetooth, and (anything around 2.4Ghz) was off.
(I only got a few minor blips from some random device.)
Then I turned on the microwave.
On all chanels, I got very heavy interfierence.
So you can also put this as a microwave detector.
Awesome project.