To recap, have you managed to get the video signal using co-ax type input but not thru the S-video/composite video. This being due to not being able to select the video input?

Thanks, and sorry for the noob question, this is really new to me.

No although it should be possible (maybe difficult to select the right channel) but not worth the effort as recording from analogue Rf in would be really poor quality.
I only record Freeview Digital with the tuner.
By the way, it records .ts files. Defaults to Documents folder for recorded files but easy to change under preferences.