I am using a 6285 (on OpenELEC) and I found it easier to add the muxes manually. The mux that carries the BBC1/2/3/4 SD channels doesn't carry anything I need so I didn't bother configuring it.
Setting up TVHeadend is a bit of a pain, but after three or four times doing it (trying different versions of OpenELEC which doesn't support TBS cards unless you build it yourself or some kind person does it for you) I found the best way was:
1) rename the tuners in the Configuration->DVB Inputs->TV Adaptors so they make sense. I called mine "TurboSight TBS 6285 #1" etc.
2) Select each tuner in turn and check Enabled and Skip Initial Scan. Uncheck everything else. Save.
3) Select the first tuner, switch to the Multiplexes tab and use "Add mux(ex) manually" to add the ones you need. I'm on Crystal Palace and I add all except the one carrying BBC SD channels. Go back to the General tab and wait until "Muxes awaiting initial scan" goes to zero.
4) On the Multipexes tab, select them all then click Copy To Other Adaptor. Select the second card and copy. Repeat for the third and fourth.
5) Go to the Services tab and for all the ones you don't want (eg porn, shopping, encrypted) uncheck the Enabled and EPG checkboxes. They ahould all be showing "unmapped" in the Channel Name column. Save.
6) Go back to the General tab, select each adaptor in turn and click "Map DVB Services To Channels". Turn on logging (upward pointing double arrow at the bottom right) and wait until idle before selecting the next adaptor.
7) Go back to Services and check that each enabled service has a value in the Channel Name column. If not select it and hit Map Selected.
8) Go to Configuration->Channel/EPG. Make sure the Tags setting is correct for each channel. I add another tag at this point: Favourites, and enable it for the channels I will record most of the time, ie omitting the radio and +1 channels.
9) Number all the channels in the Number column.
10) Switch to Electronic Program Guide and select Favorites from the Filter Tag selector. Check that the channels which appear are the ones you want.
I think that's right - I didn't write down the steps as I was doing it. It takes about two hours and you just have to get through it.
One thing which puzzles me is that in the EPG page, the programmes appear sorted by time, but I would have expected a subsort by channel number, however they just seem random. For example for 20:00 today I see BBC Four HD, then Pick, then 4Seven then Channel 4 - apparently random.
