I am primarily software. I do debug and test a lot of hardware, so I know enough to be dangerous.
Twenty years ago we built Panasonic-compatible analog-signalling PCBs for controlling Panasonic's line of "hybrid" telephones.
What I remember was that it provided power and signalling over a single pair, much line a telephone line itself if you consider the audio to be the signalling.
I would like to reproduce this configuration with the following specifications: the signalling will be a continuous 50% duty-cycle clock with a possible range of 5 to 20 MHz, the DC supply would be in the range of 9V to 24V, with a maximum of 600ma at 5V needing to be produced at the far end (using a SimpleSwitcher). This would be using a twisted-pair ethernet-style cable.
I was thinking there are probably 10 different ways to accomplish this, and numerous what-ifs are swirling around in my head. But since I've little experience in the analog possibilities, I thought I might ask some experts.
Any suggestions would be appreciated. My main goals are: cheap, simple, hand-solderable, and minimum PCB real estate.
Thanks in advance.