Could a directional antenna help with locating RF sources? There's some older work ("WokFi") on parabolic antennas for WiFi, https://web.archive.org/web/20140802123553/http://www.usbwif...
Here's another circuit design for AD8317, https://g8rwg.uk/articles/noise-meter-ad8317/
> The AD8317 module I’m using has the logarithmic slope set to 22mV/dB. I used the output of a Viavi JD785 at different frequencies to check the slope and dynamic range of the device. Linearity and dynamic range at 1GHz and 3.5GHz is good and as expected drops off at 144MHz and 6GHz.