*arf*
I for my part remembered a highly unusual amount of Signal Sources during my trip 6500LY out 2 weeks ago.
So many, I actually complained about it in the forum. And back then running in an entirely unarmed Exploration Asp, I didn't venture into any of these many except one (4 Pirates in Cobras and Sidewinders).
Notably, it as in a very narrow area between 900 and 1000LY from SOL, just before leaving the spawn-bubble for Signal Sources and it was most pronounced in one single System I scanned, where it essentially peaked.
Back then, it was just highly unusual - but I registered it as more of an annoyance.
But despite trying to reconstruct my Routing and recreate it - so far I failed to reproduce anything like it.
It was between two easy-to-remember Waypoints I noted on paper, between HIP 102681 on course to HD 184388 (at -300 Y-Coordinate because my far Destination was at the same elevation).
I'll call it a day for now, the only Signal Sources I encountered were Weak Signal Sources at a rate of one every ~2 hours - only saw Hydrogen Fuel and Microbial Furnaces (illegal Salvage).
Eventually, I may move to the magic 1000LY barrier and return to 0 Y-Coordinate levels. If nothing unusual pops up, I'll return to my home Station and abandon that search for the proverbial Higgs Boson in the Haystack.
Way too frustrating.