NTSC Degrees to Nanoseconds to Cable Length
    
 
Degrees of Time in % Vel. of Prop.
Subcarrier Nanoseconds Cable length in feet
    66% 78% 82%
1 0.776 0.5 0.6 0.63
2 1.552 1 1.2 1.25
3 2.328 1.5 1.8 1.9
4 3.104 2 2.4 2.5
5 3.88 2.5 3 3.1
6 4.656 3 3.6 3.8
7 5.432 3.5 4.2 4.4
8 6.208 4 4.8 5
9 6.984 4.5 5.4 5.6
10 7.76 5 6 6.3
20 15.52 10.1 11.9 12.1
30 23.28 15.1 17.9 18.8
40 31.04 20.1 23.8 25
50 38.801 25.2 29.8 31.3
100 77.601 50.4 59.6 62.6
200 155.203 100.7 119.2 125.2
300 232.804 151.1 178.8 187.9
360 279.365 181.3 214.6 225.4
   
(NTSC subcarrier frequency is 3.579545 MHz, or 1 cycle or subcarrier every 0.0000002793 seconds.
That's one full cycle or 360 degrees, so 1 degree of subcarriers 0.000000000776 seconds or 0.776 nanoseconds.
These numbers have been rounded off, but accuracy here is enough to time a video system within .025 degrees.)