I got a pair of HDMI Cat5 extender, it's not the HDMI over IP type, so that it's not to be used in an existing network but one to one connection only, it only make use of the Cat5 cable, I am curious to know how it actually works. Does it carry the standard "logic voltage" of 5V ? as far as I can see the transmitter takes 12V DC power supply where doesn't need power adapter at the receiver, the power is carry over from the transmitter, so that the Cat5 cable is delivering 12V as well. I asked since it is Cat5, it can be mixed up with other network equipment easily by mistake, could blow things up if mis-used.

In the past I have used CAT 5 extenders for USB, VGA and NTSC video with decent results. I've never played with HDMI extenders as of yet but you probably do not want to plug it into a normal network. You can probably say the same thing with passive POE injectors which can be 48 VDC. You don't want to plug the other end into a non POE device.

I didn't know there was one for Cat5. I thought the wiring had to be Cat6 or greater. That being said I know a few places that use those and it's no different than a direct run of hdmi cable. Works out well. These dedicated lines should be marked to prevent attaching to them.

There are 2 types of such extender, one is like mine simply to use the cable to extend the distance but did not follow network protocol, where the other is IP based, can be plug into the network to share the video network-wide. I tried the latter and find that does not work very well due to network congestion, so that for one to one sharing the simple type should be used instead.