I run my voom on 2 tvs, one HD (through the component cables) and one old Zenith with only a coax input in my exercise room. I run the cable out of the Voom box to the old TV. It works fine except for a very jerky picture on all of the stations. It does not do this on my HDTV. Anyone know why? Maybe a cheap coax cable left from my adelphia cable that I'm using?