Klaas Robers wrote: For the 405 line BBC-1 transmissions this 625 line signal was electronically converted to 405 lines by a tube-capacitor frame translator. It was a monster of a thing, but it worked!
See the difference of culture, and how to handle things.
In France, colour started in 1967 on channel 2 and 1972 on channel 3 of ORTF.
The first channel was still in black and white and 819 line standard. This was later renamed TF1.
The colourisation process started in late 1975 until 1983.
First they started to use the unused time on FR3. There was a testcard all day long and programs started in the evening.
So during the day TF1 was aired on FR3 in full SÉCAM colours. ( At that point FR3 was not covering all the country ).
The only program still produced in 819 line black and white was the news reports, especially for studio.
And it was converted… «electronically» but the french way.
They used a 625 line monochrome monitor and pointed a 819 line camera to it…
Later, everything was in colour but the stock exchange report. They used the same screen to camera method, and they somtimes applied a colour filter onto the signal.
But, they also had to do this to each transmitter in the country.
In parallel they built a 4th network for TF1 in colour and 625 line.
In the early 80's most people forgot about the 819 line channel, and it was discarted.
Transmitters were adapted to 625 line colour and we got the 4th channel CANAL+ in 1984.
That's why it was in VHF and not UHF.
( today we still find VHF antennas pointing to old ORTF or CANAL+ transmitters that doesn't exists anymore )
But this is my point, the british built a 405 line amazing converter, and the french just didn't bother and pointed a camera at a screen