Curious- with many tubes of the same type, getters can be in different locations. For instance, some 6JE6's have them at the top of the tube, and others are on the sides.

I would think different tube numbers are engineered to place them in the best possible position, but why put them in different places in two tubes of the same type?

Presumably for the same reasons that tubes of the same type from different manufacturers often look somewhat different inside. Manufacturers tries to reuse as many parts as they could between different tubes, to limit the amount of tooling needed to roll out a new type. The same plate structure might be used in several different sweep tubes, and if the getter mounting tap is already available for welding to the side rather than the top, that's where it ends up.

Curious- with many tubes of the same type, getters can be in different locations. For instance, some 6JE6's have them at the top of the tube, and others are on the sides.

I would think different tube numbers are engineered to place them in the best possible position, but why put them in different places in two tubes of the same type?

Could even be patent related.... Can you imagine the patent fights that tube manufacturers would have gone through if they fought like today's cell phone manufacturers do over their so called smart-phones.... I think apple has a parent that basically reads "squared with rounded edges" and they have fought samsung on their rounded edges for a number of years..... "Glass envelope shape" lawsuit anyone.....

The lightbulb companies would claim "prior art", as most of the tube envelopes and shape designations (S, G, GT, T, etc) were adopted from incandescent lamp bulbs...

The lightbulb companies would claim "prior art", as most of the tube envelopes and shape designations (S, G, GT, T, etc) were adopted from incandescent lamp bulbs...

Well, not the light bulb companies, but the tube company being sued would claim prior art - but that's the correct idea.

Regarding "rectangular with rounded corners," that is a design patent or copyright, a different thing from a utility patent. My cousins own a consumer research company, and they have had many projects in which they were hired to do an unbiased survey of the general public to determine if there is brand confusion, that is, see if people consider one design to be "the same" as another. For example, they might pick a random sample of people exiting convenience stores, show them a beer bottle/label and ask what company they think makes that beer.