scart connections for using dvd recorder

you can't; you need two tuners

The scart will take the aerial from the digibox or VCR, DVDR or whatever and tune itself into one of the scart channels on the telly automatically. And you just plug another aerial lead into the coaxial port of the telly.

You need a two way signal splitter or an amplifier. Some amplifiers come with a number of aerial outlets. (Worth having. You can use your old equiptment for all those occasions when there is something worth watching on all the channels at the same time. Well... you never know..)

SCART connectors don't involve 'aerials'. They are base band devices - not RF. Nor does the TV 'tune in' to a SCART. It may well automatically select any SCART device plugged into it when that is powered up.