[old_tv_nut]

Stations already had 24 fps telecines, used for regular films. These required various modifications in the projector mechanisms and light sources compared to theater projectors, depending on the particular pickup device (iconoscopes at first, vidicons later on), and might require complex or maybe impossible modifications to run at either 24 or 30. It made more sense to engineer the kinescope recorders (used in small numbers) to use 24 fps than to try to get every station using the recordings to modify or replace their telecines.

Europe did use 25 fps for kine recording. Their telecines also ran at 25 fps. It is funny to hear a U.S. film-based program broadcast in Europe at 25fps, as the actors voices go up a notch. Captain Kirk sounds noticeably different as he reads the intro to Startrek, and you do not need to hear one version immediately after the other to notice it. I got a kick out of this watching Startrek in a Swiss hotel room once.