Welcome to the forum, Srvguy
Thank you for the signal report.
If you mean WTHR NBC, real channel 13, virtual channel 13.1, then you need an antenna with more gain for VHF-High channels 7-13.
The C4 (C4V) is primarily a UHF antenna for real channels 14-51. It usually comes with a simple dipole for VHF which probably doesn't have enough gain for WTHR since it is in the attic.
You can add a VHF antenna with more gain to your C4 or switch to a UHF/VHF combo antenna.
Are you using a preamp?
The FCC says you can have an outside antenna, but you might not want to fight the HOA.
https://www.fcc.gov/media/over-air-r...n-devices-rule
https://www.fcc.gov/consumers/guides...tellite-dishes