Can you tell me if the STB sends out voltage to the winegard OTA or do I need to buy a Amp, and if the STB does what would I need to do If I want to add one or replace the winegard with a DB9 uhf antenna that is non amped.

Well covered already, hint search function try "splitter" and "DC blocker" as search terms.

Can you tell me if the STB sends out voltage to the winegard OTA or do I need to buy a Amp, and if the STB does what would I need to do If I want to add one or replace the winegard with a DB9 uhf antenna that is non amped.Yes, the STB sends out voltage via the satellite input (through the diplexer). If you are replacing an amplified antenna with a one that is not amplified, you need to replace the multiswitch with the one that doesn't pass voltage to the OTA input, or you need to install a DC blocker on that input.