What is the wire gauge on the Flex 6500 power cord?
It really doesn't matter what wire gauge you use within reason (10-12-14), the wire length, or whether in-line fuses are added. What matters is that at key-down full power output, your radio sees AT LEAST 13.8 volts at its power input. For me, that means delivering about 14.1 volts when in receive, which is well within spec. Many voltage supplies have enough adjustment that sufficient voltage can be delivered irrespective of wire gauge. Making sure that sufficient voltage delivered at max xmt ensures efficient, full power output but, more importantly for me since I only use 45-50 watts output to drive an amp, keeping the right voltage maximizes linearity and conversely results in the best (lowest level) transmit IMD.