Good advice from Benedlr instructions on how to quickly scroll (using the fast forward/rewind buttons when on a channel number, and using the circular arrow/instant replay button to toggle to previous channel).
There are a couple of ways with RokuTVs to organize the Channels (both antenna/OTA and Streaming)
1. Remove the Streaming Channels from showing while in Antenna/OTA guide. (Settings..TV Inputs..LiveTV...Manage Channels..Enable/Check box to "Hide All Streaming Channels"
The above procedure will now only show you the Antenna/OTA channels when on Antenna Input. You can now only access the Streaming Channels from within Roku Channel LiveTV.
2. Roku 10.5 OS has now added a "Manage Channels" feature to both the Antenna and the Roku Channel Live TVStreaming Channels. Basically just navigate to which ever Guide you are interested in managing, navigate to the channel number all the way to the left and press the * button (Options button), and you should see a menu of Channel Options that include Favorite, Hide, Manage, Filter, and Close/Exit.
The above procedure is how you hide Channels and create Favorites in order to get your Guide a little more organized and manageable. This is again, available for both Antenna and Roku Channel Live TV Streaming Channels. (https://support.roku.com/article/4420557730839)
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As for the navigating of the channels, go all the way to the left of the Guide and use the FF and REW buttons to scroll up or down quickly (will jump about 4 channels at a time). As mentioned by Benedlr , the Instant Replay button is used as a Previous Channel button. (You have to basically switch between the two first though before it can be used)
Hope that helps you a bit. Post back if you need more help.
^THIS msg above is indeed the best possible answer that I am aware of.
