Editing Zenith Electronics (section)

===The porthole television===
In the late 1940s, Zenith entered the television market. These sets were all-round tube sets. The main feature was that the entire round screen was exposed. They were available in 12-inch, 16-inch and 19-inch sizes. Later round-tube models had a switch that would show the picture in the 4:3 ratio, or have the entire round screen exposed. These sets are very desirable among television collectors. Many porthole sets used metal-cone CRTs, which are now scarce. It is not uncommon for collectors to replace a bad metal-cone tube with an all-glass tube. Zenith porthole sets came in tabletop models, stand-alone consoles and television/radio/phono combos.