75 ohms to 300 ohms, back to 75 ohms

[lnx64]

Here's an odd question, and it's not something I plan to do, but I'm just curious.

Lets say you have a TV that is 75 ohms coax, and you use one of those adapters to go to 300 ohm twinleads, then say plug into a cable boxes RF out via another one of those adapters.

Would that cause quality loss? Or would it cause no quality loss, if improve grounding issues, because it's isolated from ground?