Looks can be deceiving. The impedance of a video coax cable and one meant for clock signal synchronization is a bit different.
RG-58 more commonly known as consumer video cable has a lower impedance and will not work for sync'ing audio.
RG-59 is the type of cable required for digital video and audio sync applications used in professional and broadcast systems.
Looking directly at the cable, printed along the shielding will show which number it is. These are not the only two types of Coax cable, there are many others. The one you need is RG-59.
It is best to contact your favorite music product store to ask for assistance, some local guitar shops may not carry these cables. Professional Video and Studio stores and online vendors will be able to help you as well.
