Experts can you clarify: Channel-Scan/add to guide

I was just wondering if any exper TABLO users out there can explain to me if when I channel scan and say I get a slightly different set of channels back does that remove the existing channels (say I had a station that was OK but not great reception, that didn’t show up on subsequent channel scans) will selecting new channels after a scan remove any channels not found? … or is it more an “Add only” type thing where it just adds to your existing channels leaving any previously found channels as is? … (my HDTV has an “add only” type channel scan which will only add (not remove) channels found) I was wondering if the TABLO worked in a similar fashion or does it wipe your available channel listings in favor of the new set found/selected?

The last channel scan that you do will be the only channels that you will see. So yes, it will remove channels if it can’t find them in the most recent scan.

I have had a weird problem a couple of times where I would get a “weak signal” error on channels that shouldn’t be weak.  Then I did a channel scan, and the only ones that showed up were my SD channels (480i).  Going into my live tv page, that was all I would see as well.   To fix it, I had to reboot my Tablo, and run another scan.  All the channels came back.  

Thanks for the tips … I did the channel scan but likewise I lost channels I had (they werent green but orange … and came in OK) I didn’t want to loose them so I didn’t accept the changes…