Portable spectrum analyzers capable of up to 2500 MHz are not so expensive these days. I'd bring a horn antenna and spectrum analyzer and start hunting.
Here's a plot from when we discovered LED motion sensing lights use a radar signal on the upper end of 5Ghz. Every vertical line is another light. You can imagine a hallway filled with 20+.
I’ve used this for assessing some harmonics of 4-5 MHz clock lines causing issues.
Carstairs is 60 km north of Calgary where you find the Calgary Amateur Radio Association (mission: "Have Fun and Serve our Community"), University of Calgary Amateur Radio Club and other organizations, all of whom would be thrilled to break out their spectrum analyzers and nail this to the wall for free.
been lusting after one of the little guys for some time now.
I'm also kind of salty that they dropped the MicroUSB variant of the full-size model. The Mini makes sense to have it a "stick" format, the full one does not. The full one having an A connector on it has been nonsense from day one.
I still will probably end up buying one because they're still the best bang for the buck.
If you're just getting into SDR, I would just get a $20 RTL-SDR, and then move on to something like the HackRF or BladeRF later.
The Red Pitaya is a particularly compelling alternative from a hardware hacker's perspective, because it does double duty as an extremely versatile measurement and data acquisition device.
Just use a rubberducky antenna (a stick - heck, just a piece of wire), and measure relative intensities in a few points on the map. That will give you an idea where the epicenter is.
Then walk through that area while keeping an eye on the intensity. I betcha you will bump right into the culprit.