May I know the type screw in powerful antenna you bought. What are its specifications. I want yo find something similar from my suppliers here.
I purchased my replacement antennae from an Amazon seller (not ebay as I said before!) They are "Super Power Supply" based in Indiana, USA.
https://www.amazon.co.uk/s?merchant=ASE9NB3G8DVCM
But take care, this may NOT solve your problem if your router is in a different room from the Q10 with brick walls in the way! As others have said here, a wired Cat6a Ethernet cable connecting your router to your Q10 is the BEST solution for streaming video from Netflix, Amazon, Google, YouTube ...