I ran a rg6 line as a temp to a trunk amp for almost a month. 60 volts w/ a return for modems and digital boxes. No voltage degridation that anyone noticed. The amount of misinformation is astounding. I see why the companies that run installer contracts pay peanuts. Learn a little about your trade and you might make some $$$$$$$$$.
This is CABL.com posting #273651. Tiny Link: cabl.co/mbjlT