Do an FTA scan first. That way all your FTA channels will be ligned up first on the channels list.
Then you can go back and do an ALL scan. It will put the scrambled channels at the end of the channels list.
Then go through the channel list and check what $$ channels if any are actually FTA (like the example given by ICEBERG). Sometimes a scrambled channel might be in the clear for a few days for promotional purposes.
After that go the CHANNEL EDIT menu and delete all the channels that have $$ and are not FTA. That will keep your list of channels clean.