Hi old_tv_nut,
You're welcome!
You asked: "Did you ever see the 819 line broadcasts? Any comments on the quality?"
Sure i did! i'm 57 years old and got interested in TV around 1960 at age 7. My grandmother had a 17" B&W 819 line TV and i clearly remember seeing the 800 pts/line bars resolved clearly on the test pattern shown below. This test pattern is known as "The Chevaux de Marly" - Marly horses because of the equestrian statue shown in the central photograph.
In 1964 the second TV program opened in 625 lines UHF whereas 819 line service continued in VHF bands I & III. A new color UHF/SECAM/625 service was created starting in 1968 to duplicate in color the entire 1st TV channel network nation-wide, this was called "duplication". The 819 line service was shut down in 1985 when the 625 color service covered the entire country.
Very interestingly, the British followed exactly the same path with the 405/625 service for BBC-1.
As for today, some french TV vintage collectors are hoping to see full resolution 819 lines again by using the Y channel of a BluRay DVD cracked with the HDFury decoder device:
http://www.hdfury.com/ and some big help from Darryl to make a special wideband version of his 819 converter.
From memory, the 819 line system E specs allocated 8.75 MHz bandwith to the video signal and the entire channel occupied 13.15 MHz.
Best Regards
jhalphen
Paris/France