MA
BBC was about 1956, Channel ITV opened in 1962
When did the channel islands get VHF transmitters for both BBC and ITV?
BBC was about 1956, Channel ITV opened in 1962
MA
Some of the DTT relay daisy chains in Wales and Scotland that are 5 or 6 stations long introduce ( because of reclocking) a total delay of 15 to 20 seconds I'm told!
It used to take about 25 minutes to bring the whole BBC chain up, from Crystal Palace to Baltasound, which is why pulse and bar was radiated for 30 minutes before Test Card F or Ceefax in Vision.
Some of the DTT relay daisy chains in Wales and Scotland that are 5 or 6 stations long introduce ( because of reclocking) a total delay of 15 to 20 seconds I'm told!
MA
Would that have been an issue in 1979? The transmitters were switched off every night and always came back on. Probably more of a issue with the older 405 line ones too
It was an issue years later once things went 24 hours. I remember being told that when the original BBC UHF transmitters were replaced they had trouble turning the outgoing ones off as the switches that once were used every night hadn't been used for years and wouldn't turn off. They had to turn the main breakers off instead
I'm presuming that the worry was a prolonged switch off rather than overnight. Some equipment would have been live during the overnight closure, heating circuitry etc. especially on the high powered ones. A complete shutdown would be different.
The risk of damage occurred if the Klystron beam current was applied before the heaters had done their work, they were full of interlocks to prevent this. I'll ask someone in the know whether the heaters were left on permanently
Would that have been an issue in 1979? The transmitters were switched off every night and always came back on. Probably more of a issue with the older 405 line ones too
It was an issue years later once things went 24 hours. I remember being told that when the original BBC UHF transmitters were replaced they had trouble turning the outgoing ones off as the switches that once were used every night hadn't been used for years and wouldn't turn off. They had to turn the main breakers off instead
I'm presuming that the worry was a prolonged switch off rather than overnight. Some equipment would have been live during the overnight closure, heating circuitry etc. especially on the high powered ones. A complete shutdown would be different.
The risk of damage occurred if the Klystron beam current was applied before the heaters had done their work, they were full of interlocks to prevent this. I'll ask someone in the know whether the heaters were left on permanently
MA
JK
BBC Television launched from the Les Platons transmitter on St Helier on Monday 3rd October 1955. ITV in the Channel Islands launched on Saturday 1st September 1962 from the Fremont Point transmitter on St Helier.
When did the channel islands get VHF transmitters for both BBC and ITV?
BBC Television launched from the Les Platons transmitter on St Helier on Monday 3rd October 1955. ITV in the Channel Islands launched on Saturday 1st September 1962 from the Fremont Point transmitter on St Helier.
IS
They're not part of the UK
BBC One, BBC Two and Channel Television in colour on the UHF 625 line service launched from Fremont Point on Saturday 24th July 1976 - the islands where the last part of the UK to receive BBC Two and colour television.
They're not part of the UK
Last edited by Inspector Sands on 21 August 2019 5:41am