Don't laugh. This makes sense in my head, I just don't know if it exists in the real world. I'm trying to pin down some wireless issues in a venue, across different types of gear (headset, mics, DMX, etc). Is there a device that would let me scan to see what frequencies are in use around me? Something I could borrow or rent? It seems like there must be something, since I've heard of wireless phone carriers driving and scanning their frequency ranges. I know Sure and Senheiser list frequencies in a given area, but I'm seeing weird changes over the course of a day, and I'm trying to figure out exactly what's happening. Doesn't help that the venue is right next to a large cell and radio tower.