[Radioroslyn]

It may be a little confusing but tubes that start with a 7 or 14 tell us that they are Loctal tubes (99% of the time) The 7 also indicates the it has a 6.3v heater and 14 has a 12.6v heater (99% of the time) There are a few odd ball tubes that don't fit in to this scheme. Philco is the early 30's made a #14 tube but it was used in their 110vdc sets. It's an old standard base tube. In the late 50's some tv's had some odd ball 7v tubes like a 7AU7 which is a 9pin miniature. So there are a few exception but not a lot.
So to be picky about it it's 6.3vX4=25.2.