[MrRadar]

In theory the electromagnets controlling the vertical and horizontal sweep of the electron beam should react instantly to the incoming sync signals but in practice it's much more complicated (because the magnetic fields store energy which you need to deal with somehow). Bob Anderson has an entry in his series on the general process of restoring vintage televisions which goes in depth on the topic: https://www.youtube.com/watch?v=HdEfo8jS3FI&list=PL4aHiwoXvL...