[time-nuts] Measuring TV delays

[Magnus Danielson]

Bill,

On 02/01/14 20:33, Bill Hawkins wrote:
> IIRC, the reason why NTSC has an almost 30 fps rate is that early
> vacuum tube TV sets could develop heater-cathode leakage that
> would put a black "hum bar" in the picture. Almost 30 allows the
> bar to move through the picture in a 60 Hz power distribution
> system. Seems like Europe would have had that problem.
>
> No need for it now, but it's like the QWERTY keyboard . . .

Wouln't help that much, since the power-grids 60 Hz vary over more 
frequency, than the 1/1.001 offset gives, which is about 59.94 Hz, and 
over the coarse of a day it varies more than 60 mHz.

Cheers,
Magnus