video wiring upgrade?

MrWizard wrote:
Any cable is nothing but wire
Any signal that is not RF and radiate a broadcast signal can be sent over any wire
USB cables, Ethernet cable, phone line, HDMI cable, it is just wire
You just need the correct number of wires
Why do you think there are hdmi over Ethernet cable adapters
Of which a link has been posted with the suggesting to pull Ethernet cable in the RV
No difference using rgb cable
In fact rgb should have less loss and less possible interference, because each cable is a shielded wire larger guage than hdmi or Ethernet

Suggesting that all wires are more or less equivalent is like suggesting that all roads are equivalently suitable for any driving. A forest service road and a multilane superhighway may be about equal for some uses (it's not much more difficult to walk the dog along either one, assuming there's no traffic), but for driving a convoy of semi trucks at 65 mph only one would work properly.

Similarly, there are significant differences in wire types for high speed data (be it analog or digital), and video certainly qualifies. HDMI is very different electrically from analog component video; it's digital signaling well in the GHz range, and impedance mismatches from inappropriate cables will cause reflections etc. that will absolutely render the signal unusable. Furthermore, it uses balanced differential signaling, so each of the main video signals is a twisted pair of wires, while analog component video is typically unbalanced. Many wires would have excessive capacitance that would attenuate such high-frequency signals unacceptably. (HDMI is also rather sensitive to small differences in length between the various wires, and hence skew between the signals sent over the wire. A few inches difference in the total length between the various wires is quite sufficient to make things not work.)

HDMI over ethernet adapter are not merely connecting the wires of one to the other. Rather, they have a video encoder (compressor) chip that converts the raw digital video data from the HDMI signal into compressed video and sends that over ethernet, with a decoder at the other end. The resulting video is not bit-for-bit identical to the input in general, though it's rare that you would be able to notice the differences visually.

Similarly, running (twisted-pair) ethernet over a set of coaxial cables would generally not work very well. There were 10 Mbit coax ethernet systems that were popular at one time, with a single coaxial cable connecting all the computers together, but that system isn't really used anymore and doesn't support 100 Mbit or faster ethernet.

For short distances and lower bandwidth signals, you can often get away with less than ideal wiring. As the distances increase and the baud rates go up, the specifics of the cabling become very much more important.