I am seriously considering moving to freesat at my new place (I'm in the UK).
1. Does freesat still have multiplexes like with freeview? If so, how many? Can one tuner handle all the viewing/recording of all the channels on a given multiplex? (I will be using myth).
2. What DVB-S2 card is best to use? I am currently on 1004, will be using myth, don't mind if it's PCI or PCIe. Less keen on USB, but fine with it if it's known to be working.
3. Once I understand the above, the next question is how many tuners, and how does that impact which dish I choose? Currently I use 4 tuners for freeview, but I think I could probably get away with 2, I record so much crap that I never ever watch.
1. Yes multiplexes similar to DVB-T. The number of frequencies (called "transponders" in sat lingo) are much higher though. One tuner can provide the full stream to Myth, that can then record whichever MUX needed, including several.
Please look at http://www.lyngsat.com/28east.html
There you can see the transponders, and the channels on each. Most carry 6-10 free channels, but some are probably not interesting to record simultaneously - like Channel 5 region 1, 3, 4, and 5
2. Can not really guide you there, since I am using virtual Core (actually 8.10), thus my tuners are USB - and a struggle on 8.10, meaning I will be upgrading to 10.04 where they should work fine. Just ensure you buy DVB-S2 tuners, where both DVB-S and DVB-S2 is supported in 10.04. (bet 10 beers that Andrew http://forum.linuxmce.org/index.php?action=profile;u=38882
can tell you, although 10.10 could vary in HW support compared to 10.04)
3. Like I mentioned above, you would need more tuners for sat... The dish can be whatever, but the microwave head (the LNB) need to be for enough tuners. I would recommend a "quad" LNB (not a Quattro, since these requires a special switch), or if you are ambitious an "Octo" LNB for 4 resp. 8 tuners. The price between single, dual and quad LNBs are very small... And I am quite sure you can find PCI(e) cards with 2 tuners quite cheap.
If you want premium channels (SKY) then this is also possible (and legal), but policies here states that this should not be discussed - I actually disagree with these policies, but can easily understand them, since the step to implement viewing paid TV legally is actually a (very small) bit more complicated then the steps needed to watch the same channels illegally...
You could also consider a slightly larger dish, with 2 (or more) heads (LNBs) for receiving many channels from across the continent - I personally scored tremendous with the wife when I tuned to "Abu Dhabi Sports" to find live broadcast from World Championships in endurance horse riding (which is her passion, mine is sat tv ;-) that wasn't aired in any "normal" tv station..