Color TV Porthole sets?

[Aussie Bloke]

I recall asking about the porthole colour sets a few years back. Just wondering in general when viewing a picture on the bare round tube outside of its bezel does the picture only extend so far up the tube before being cut off or does it extend all the way to the top?

[VintagePC]

Originally Posted by Aussie Bloke

I recall asking about the porthole colour sets a few years back. Just wondering in general when viewing a picture on the bare round tube outside of its bezel does the picture only extend so far up the tube before being cut off or does it extend all the way to the top?

Only as far as the phosphor coating on the face. Remember that the rest of the tube has to have an electrically conductive material on it to make it a capacitor.