When I do a channel scan for OTA local channels on my Roku TV not all channels appear. Using the same antenna I can pick up more channels on other TVs. It is possible to "Hide" channels, but I see no way to add missing channels. On a regular TV I would just tune to the desired channel using the number pad and adjust the antenna for good reception even if the channel scan did not find it initially. The Roku TV has no number pad and I can't figure a way to manually add an OTA channel. Any suggestions?