To be sure I understand, are you saying you connected an over-the-air antenna to the antenna input on your TV?
If so, your TV has to do a scan of the digital channels received by the antenna before you'll see any live local channels on the TV. The controls to do this are accessed through your TV's menu system, often in a "Setup" section. Note this is a function of your TV and the Roku has nothing to do with it.
Roku Community Streaming Expert I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well. If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
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A TV with a Roku attached is not a Roku TV. It's a TV with a Roku attached.
A Roku TV is a TV that has built-in Roku menus and functionality. It also has standard TV functionality; after all, it's a TV.
A Roku TV has the inputs for the TV just like any other TV. After all, it's a TV.
A Roku Stick (or set top box) doesn't have antenna inputs. It's not a TV. It's a device that attaches to a TV.
Connecting an antenna to your TV is independent of having a Roku Stick. If you connect your antenna to your TV, you'd watch TV by changing your Source to TV/Antenna (or however the manufacturer labels it) and not on HDMI 1 (or whichever HDMI port you have your Stick connected).
You'll have to do the scan of channels, as was mentioned earlier, before you'll be able to watch TV. But you'll be watching it on a different TV source than the Roku.
DBDukes Roku Community Streaming Expert Note: I am not a Roku employee.
If this post solves your problem please help others find this answer and click "Accept as Solution."