RG-6 is preferred.
However, it really depends on the length of the cable and the signal levels you need.
The problem with FIOS is the MOCA signals are in the upper frequency band (which have greater signal loss) and my be impacted more by using RG-59. You may have good TV performance, but have erratic/intermittent or no STB networking with RG-59.
RG-59 has more loss than RG-6 but may work.
Only 1 way to really tell, connected up and see what the signal levels are and if they are acceptable.
Written by fiosfaq
Last updated on 12.18.06