Quote Originally Posted by Smokey View Post
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And why would that be? {coax cable actual impedance much less that 75 ohms}

One specifcation of [quality] digital coaxial cable is is having 75 ohm impedance (same with video cables too).
No need to take my word for it. Grab yourself a length of coax and measure the resistance with you handy dandy multimeter. I just now took a 6' length and measured: signal (core) = 0.3 ohms; ground (shield) = 0.7 ohms.