I was unable to find a description of how the blanking periods worked in System 3. However, frustratingly, despite being the main citation, System 3 is not the CBS color system that was adopted in 1951! The first citation I could find proving this was this 1951 Radio and Television News article, transcribed here. But yes, this was a 144Hz system! Presumably that adjustment was made after 1942.
Европейская страна обвинила США и Израиль в нарушении международного права20:06
，更多细节参见新收录的资料
In October, official ID photos of around 70,000 users that Discord had gathered from a previous age-verification partnership were likely leaked through a cyber-attack.，这一点在新收录的资料中也有详细论述
（一）记录信息包含本法第七十四条相关内容，并可供调取查用；，这一点在新收录的资料中也有详细论述