21-08-2023, 12:03 PM
(20-08-2023, 02:20 PM)Stooky Bill Wrote: That's a bit different, that's an OB failing. Yes you are seeing a main and reserve, but they'll both be into ITV presentation and the transmission controller/director will have needed to cut the reserve to air.
The source that says 'no signal detected' is a satellite receiver/decoder, the colour bars are from SIS, looks like some sort of decoder (and interesting spelling of 'media'). Both of those will either be synchronised into the building, or a local device so end up on air as proper good video, there'll be no loss of signal into the TX chain and it won't try and switch paths.
That breakdown is a good example of path diversity. They had a main and a reserve, looks like they were being downlinked in two places, and they maybe were using two satellites.... but the single point of failure was the the weather. It's why broadcasters specify two diverse routes, but that's not always possible. Easier these days as IP solutions are improved, you can get a land based link from more places than ever
Incidently I remember being told that OnDigital's two diverse transmission paths originally went over the same bridge
Am I right in thinking this particular problem was quickly overcome by an enterprising links engineer pointing a conventional microwave dish towards BBC tv centre where the signal was picked up and relayed to BT tower then onwards to Chiswick?