User:Azeem4Hadzrie/Mysteries/Anthem

What We Know:


 * Known as a "secret", every sign-off has an "national anthem" before disabling its transmitters, or heading to color bars.
 * Not all channels follow this way, mostly on cable and satellite. For example, after HBO signs off, it will instead play dual tones twice. Another example is when Cartoon Network signing off to another network, Adult Swim - when it switches over to an warning screen that programs may not be suitable for their young ages.
 * After the National Anthem, it was quite remembered that static will play (resembles the transmitters were closed down through the night). This practice was ended during the 80's, when transmitters discontinued to close down through the night.