Just watched the Thailand Grand Prix (a one-star tournament) on cable. Although Robertson is wearing black Carlton jersey (quite cool !), but I can't identify his rackect since he didn't spray the logo onto the string. So I just wonder what he is playing with.
No idea, but you might get an answer by posting the same question on www.badders.com but then again you might not.
Last I saw, he was using a Carlton. Not that familiar with Carlton racquets but it looks like a Powerflo 700GR. Usually if they are wearing a vendor shirt, they are using the vendor's racquet. Exceptions are if they already have a clothing deal with another non-racquet company (e.g. Gade, Audina,etc).