The numbers look kind of low don't they? These are for DC continuous duty cycle. Many manufacturers of mobile and 100W tranceivers ship a 12 GA power cablke for DC operation. I consider this too small and prefer a minimum 10GA. I run 6 or 8 GA in my mobiles ( also using silver plated with many more strands than the hardware store variety ). We just installed #8 on a 240 line in the house for AC that mfg specified as a 40 amp circuit - way more than the AC uses. I don't spec my DC operating Cables on basis of maximum current carrying capability, but rather for best DC resistance characteristics. Remember Ohms law when applying current to a DC supply, If you are running a 100 watt transceiver with a nominal 20 amps at voice peak on transmit and you have as little as 0.1 Ohm resistance in the power supply circuit, your supply voltage at 13.8 VDC will drop 2 VOLTS! That's at current (VOICE/CW) peaks when you need them the most. Also, judging wire gauge by insulation (85C for instance) will not be a valid measurement unless you actually plan to run currents that will generate heat in that cable. That would be a sure indication of IR losses that are way beyond anything you want to have i.e. for that 2 volt loss you'd be seeing 40 watts going into heating. Also remember that the connection points (terminals) are most likely the highest resistance points. Being concentrated heating points the terminals are usually where fires get started when they are dissipating too much heat. 40 watts is about what the average soldering iron provides (doing soldering jobs in ham rigs), so you could conceivably desolder a poorly done terminal if it has as little as 0.1 Ohm resistance. de AL, WA6VNN
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