Just an update: Tech came out today and measured from pedestal to demarc and said downstream signals were OK but not ideal, and agreed upstream signals are too low. He replaced the box (coupler) at the demarc, then measured on the line from the demarc to the outlet, and said the line from the demarc to the outlet should be re-run.
He was exceptionally nice and I was very impressed with him. He will return in the morning to run the new line in our attic before the temperature hits broil.
After replacing the coupler, did Down become "ideal"? How does a cable go bad in 1 week?
I'm just relaying what the tech observed. The cable run in the attic is basically in a summer roaster and after, what, twenty years (?) the heat maybe has gotten to it and the impedance finally just hit the "straw that broke the camel's back" moment. I don't have a hard answer at this point. I don't know why the Cox tech from years ago put a splitter on that line, but he did. We will see if the new run fixes the issue.
I completely understand the purpose of a splitter; my point was that there was no *need* for a splitter on our setup. There's just no rationale for it - feed should go straight to the drop in my office. And Cox was the one that put it in years ago.
Your attic must be some roaster. Even the cheapest coax can survive 175º and probably more since it's not dry-rotting in sunlight.
After the tech yanks it, I'd check the cable for any obvious chaffing or severe kinks. If so, yeah, probably a bad cable. If not and the tech also suspects heat, will the tech replace with higher-quality (Ethylene, Propylene, PVC) or just what's in the truck?
I have no insight into what media he will use to run the new line.
