Did the 1977 Southern TV interruption actually come from somewhere local?

Always thought it was odd that the signal supposedly came from somewhere in the south of England and yet nobody nearby reported anything unusual that night, no strange vehicles, no dodgy equipment, nothing. Living in Essex I feel like someone round here would have noticed a massive transmitter setup in a field. The "Vrillon" voice was so clean and clear for 1977 tech as well, almost suspiciously broadcast-quality. My mate reckons it was a student prank that got wildly out of hand but I dunno, the message itself is a bit too polished for some bloke mucking about in his garage. Anyone else think the location angle has never been properly investigated?