Virgin 1 becomes Channel One

It's just a generic caption. As BSkyB aren't particularly bothered about Freeview, then it will probably remain for a while.

The replacement channel from BSkyB (Challenge) is on a different Mux, apparently.

It's on 46 on the freeview EPG.

Yes it is

How's that come about then? I thought there was sod all capacity on DTT, let alone space for channels to hop about?

I'm not sure what you mean? You don't need spacee to "hop about". Channel 1 has shut and been replced by Challenge, but ti couldn't use the same LCN as it's not a stright rebrand.

So it hasn't moved to a different Mux?

Mux A.

Channel One was on Mux D.

So where has the space on Mux D come from?

I see some of the Daytime shows from Channel one have gone to Sky atlantic

Ahh, sorry, see what you mean, me not reading things properly.

Challenge is in a new 24 hour slot announced by Arquiva last year as a result of improved compression techniques.

I see, does that mean Sky have purchased that space along with the space Channel One previously used? Or is Channel One's slot now up for grabs?

Challenge is definitely on Mux A where it is a straight replacement for Channel One. There has been no new capacity added at this time.

http://www.dmol.co.uk/mux.php

http://www.dttmuxes.co.uk/

http://www.unsatisfactorysoftware.co.uk/dtt/dtt.cgi

http://en.wikipedia.org/wiki/List_of_digital_terrestrial_television_channels_(UK)