Colin,
My mistake, I missed that part of your explanation. I guess a lot of the confusion comes from the view that most of us who are "not in the know" assuming NTSC=US and PAL=UK. SECAM=France. I guess all the standards get used elsewhere and with different parameters.
The analogy I was trying to make, however, stands and my question has been answered (a PAL tv won't playback an NTSC signal and I was worried that an SD TV when connected to an MD with an HD recording would similarly have "issues"). I now have it clear in my head (thanks to you) that the HD/SD issue when talking about the broadcast, recording and the link between the MD and the core is separate from the one when dealing with the display device and the link between it and the MD.
I was assuming that transcoding would happen on the core, whereas in fact that process (which is really rescaling) happens in real-time on the MD.
So......
If I install some kind of HD reception system in my core, I will be able to watch them on my current SD screens and, when I upgrade some to HD, I will see the benefit. My MCE system and my recordings are future-proofed and that's what I wanted to know
Thanks, again, for taking the time to respond and clarify this for me.
I need to be VERY clear what I can achieve if I'm going to get the all-important sign-off from the management committee (AKA my good lady wife (chair) and our offspring)