04-07-2021, 07:29 AM
Si-Co post_id=25656 time= user_id=1388 Wrote:Inspector Sands post_id=25603 time= user_id=1003 Wrote:Markymark post_id=25597 time= user_id=1078 Wrote:Actually the clues are possibly contained within that programme. They stated that BT had completed the automated switching mods. So that frame roll must have been at 09:15:00, and what we see is Sutton Coldfield etc being switched by BT Brum from TV-am national station output to Central Birmingham's o/p. At the same time BT in London replace TV-am station output with IBA Crawley Court on the 'ITV' national dist, and Central fade up the IBA feed at 09:15:05.Yep although of course they didn't have to switch/route the output of Crawley Court to the ITV companies at exactly 09:15, that could have been done at any time before
Actually the frame roll in that recording comes at a random time of about 09:15:35 (and Engineering Announcements lasts only eight minutes). I assume the IBA caption and music before EA is also being sent to Channel 4? Other than that, I agree with your thoughts.
How did you deduce the apparent line switch was at 09:15:35, back timing from the schools clock starting at 09:29:00?
Yes, the IBA caption and music started up on C4 at 09:10 ish. However, how could the IBA feed have been fed to the ITV companies in advance of 09:15 (ish) when the ITV national distribution was still carrying TV-am? That was the whole point of BT's regional switching, to locally 'trombone' the local company back into circuit at 09:15, (09:25 once automated)