I use a 12v powered hub from Startech. Mine is a 7 port (my laptop only has a single USB3) but I know others here use the 4 port version. As for where position it, I work mine out so I have the least number of cables coming off the moving parts of the scope/mount as possible. Right now it's mounted on the OTA dovetail bar, but new gear arrived today so that will be changing yet again.
