It is likely that the TV aerial on your house points 35km northwest toward the transmitter at Winter Hill, if so you should be able to plug-and-go with a Freeview box using your existing (group C/D positioned horizontally) roof-top TV aerial.

Some channels (click here for list) are on lower power so you may be able to receive some but not all.

Your aerial could also point 85km west-southwest toward the transmitter at Moel-Y-Parc, which you cannot receive Freeview from (but you can see analogue channels).

Your aerial could also point 12km north-northeast toward the transmitter at Saddleworth, which you cannot receive Freeview from (but you can see analogue channels).
 

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