Just bought a new TV! It's "smart" but where my previous dumb TV didn't, my smart TV introduces a delay over HDMI from my Sky+HD box compared to the RF2 output which is wired via coax cable to the other 3 TV's in the house. My research tells me this is likely due to the way the smart TV decrypts the HDMI feed. My 3 dumb peripheral TV's do not have any facility to introduce a delay so I have to ensure the volume is low on the kitchen TV otherwise there is a fiendish echo. I have previously enjoyed electronic construction and am intrigued to know if I have any chance of being able to construct a circuit that could introduce a delay into the RF feed, preferably the powered RF2 output from the Sky box. I believe coax cable can be modelled to the following circuitry:
It therefore seems to me that if I was able to calculate values for these components, I might be able to introduce a variable phase shift that would solve my problem. That is, I might fool the feed to think that the cable was a mile long. Perhaps that would result in signal loss/degradation? Can a 200ms delay be done? If so, how? I have found that one can purchase HDMI splitters and modulators. Perhaps that is a more logical approach, for example, that I distribute the split HDMI feed over the coax lines? However, I suspect I might still end up with asynchronous results. I really have done a lot of research and will do more, but would value all opinions and advice. Thank you in anticipation.