Wow! First off, do not hook-up that antenna into your existing cabling until you have cut-off the cable service.
Pulling-up a cable from your insulation and cutting it is very risky. Why do it? Locate the point where your cable enters your attic. Disconnect the cable from that point. If the cable runs to your splitter, then you may connect it to your antenna balun.
Three simple steps:
- Disconnect attic cable from entry point.
- Move attic cable to antenna.
- Connect attic cable to antenna balun.