[Alex KL-1]

Intereting!
But, a compatible TV is needed, also. Or a converter, to see the results.

Back some almost 30 years I first read about the TV systems, I simply played with the calculator, and "devised" a system mixing the US and European high specs: 625 lines / 60Hz vertical scan rate ("625i/60"). H rate is (if I remember well) something in the vicinity of 18.750Hz. Some 9MHz of channel bandwidth are required (or are the video response?) (only a faint memory from the calculations from theses times; I never re-calculated it again). I not calculated the sync pulses duration, but black level was like the NTSC-J.

Fast forward and I understand the world wide adoption of systems having bandwidth like the M system and the European ones (relatively close each other, due to refresh rate differences), and why the audacious French 819i system failed to survive (hard to implement; expensive, especially for tube systems).