405 vs 625 line transmission?
The 2 systems were completely different and when the UK converted to 625 lines and colour in the mid and late 60's to the full roll out to all regions in the early 70's a new transmission network was built. The UHF transmitters had smaller range than the VHF ones. For many happy years viewers in Cambridge were proud to be in the London region with dual stacked Ch9 aerials and a Ch1 aerial (huge) pointed at Croydon and Crystal Palace. Some upstart Anglia TV came along on Ch11 (poor reception) in 1959 and later in 1965 on Ch6 from Sandy Heath about 20 miles away but most stayed on London. When colour TV took off in 1971 in Cambridge viewers had to switch to Sandy Heath as London could only be received in colour on a proprietary British Relay cable TV system. Ch23 the ITV London signal was picked up in Arbury Cambridge with 8 high gain aerials at 180 ft. Still suffered from co channel interference from local Anglia on Ch24 and they fitted a specially made filter which just about made the picture from London desirable. So dual standard sets which had UHF 625 and VHF 405 lines on were around until the late 60's. I spent many "happy" hours as a junior bench engineer removing system switches and hard wiring them to 625 lines and setting the tuners to UHF only. This made the sets much more reliable. Also spent "many happy hours" sawing down ITV Ch8 Litchfield, Ch9 Croydon, Ch11 Mendlesham and BBC Ch1, London, Ch2 Cambridge, Ch10 Willington Bedford, Ch5 Peterborough aerials and swinging the odd UHF aerial around from Belmont to Sandy Heath. This was because everyone needed a new aerial when colour TV came out to the masses. I preferred my time on the bench to helping the aerial rigger and TV installer as some of those older metal aerials and poles were very heavy indeed. I was an apprentice TV Engineer from 1975 to 1979 based in Huntingdon and Cambridge and a field engineer from 1979 to 1990 when I got a bench engineer job in Peterborough.
Biting the hand that feeds IT
