Another basic question, purely as a matter of interest.

With satellite reception, why is it that some channels are stronger than others - even if they are intended to cover the same area?

Or to put it another way. If a bunch of channels are intended for the UK, shouldn't they all be the same strength (even if received in Spain). For example, some of the less popular film or music channels are sometimes a lower signal strength.

Different satellites, different beams, different polarisations (vertical and horizontal), difference FEC, different symbol rates - all affect the signal characteristics.For example, many frequencies have changed to other FECs, as error correction, means less data required on that frequency, and so more channels can be put on that frequency... but with less error correction, this results in more pixilation and seeminly lower signals...And then they can turn up and down the power output of the satellite, maybe they can do this on a transponder by transponder basis also...

Thanks for the explanation. I often miss the concept of a group of satellites at say 28.2E rather than a single one.

Is it possible for a channel to 'go off air' so to speak?

The ITV+1 that we put into favourites is now a blank screen, even though the signal strength and quality bars seem ok. So we lost our PVR recording of 'Unforgotten' last night! Trying an alternate ITV+1 seems ok.

Yes.The ITV1+1 you had in favourites probably changed frequencies.So that channel will no longer be available on your stored favourites list.So it will look as if it went "off air" - (on the 5th Nov by chance? - ITV did a few changes then - check itv4+1 also!)But there will still be other channels on that frequency - hence why you are showing you are still getting a signal.

Many thanks for your explanation. Very helpful.