After spending 2 days i gave up on this Alien Artifact hunting.
Found nothing yesterday, and the same today.
We were in a wing of 3 fighting our way through vulture and Fdl Strong signal sources with Commander Suranna and HisDudeness and it gave us exactly nothing.
In the beginning we checked every signal source but in the end we concentrated on Strongs only.
At one point Suranna found a Strong source with one AI Relics canister inside and 3 anaconda. We picked it up and all of us double checked that it didnt gave out any sound along with the ancient Artifact i found yesterday.
Also we found a strong source where 2-2 security conda escorting 1-1 type9 like we found yesterday but this time we could scan them and only found Hefnium 178 inside so there goes our theory about these escorted type9's having alien stuff inside.
At the end i found 2 Ancient Artifact again in a Weak source and that was the end of the hunt for me.
Final piece of advice: If somebody still looking and struggling to get signal sources(even with minimum thrust), just drop at your current location and jump out again. This always seemed to restart it for me when i havnt got anything for 2-3 min.