According to an old post from Inspector Sands (http://tvforum.uk/thenewsroom/nationwide-39220/ ) Guildford does/did have a facility that worked into a microwave receiver on Crystal Palace.
That was how the original DTL facility in Nottingham, before East Midlands Today was established, worked too, into the masthead receiver at Sutton Coldfield. (see http://tx.mb21.co.uk/features/coldfield/18.shtml)
Similar techniques were used for the Ipswich and Luton DTL positions I believe (microwave into a receive point also probably used for terrestrial FRV links)
I think very few of these circuits are still in use as they were PAL composite. These days an IP encoder would probably be more practical (assuming a reasonable data connection is present)