Urgh Preston.
What about Media City in Salford (not that salford is nice but at least its close to manchester which is nicer than preston). There usually engineering jobs in London. Globecast, Discovery Channel, Arqiva, BBC. I generally look on Caspian One, Christy Media, Venator Recruitment, Grapevine Jobs.
What I've learned though, is that most companies are garbage past the 'shop floor' level, so you're unlikely to be able to do a good job at any of these places let alone make any changes to help yourself do a better job. These people should be telling YOU why you should sell your time to THEM. Scumbags.