We use a FreeSat here and it works well.  Setting the postcode simply gets that region's version of BBC1 or ITV etc relevant to the postcode.  Please note that the Humax box requires a pre-amp in the form of a cheap satellite decoder from Lidl whereas the cheap and cheerful Grundig box seems to be OK without this.  As with  all satellite TV here the bigger the dish the better.  Size matters... so strap Jodrell Bank to your house in a wind shadow if you can.