[Boatanchors] Question for 6B4G

[William]

Hello All,

Today's question:  Why does a Tung Sol 6B4G have 2 plates in each bottle while the data sheet (http://frank.pocnet.net/sheets/127/6/6B4G.pdf) shows only one?

It is late at night and I admit to not examining the internals very closely as yet.  I suppose each plate is tied together as well as each grid?  Seems somewhat strange to me.  What would be the reason or the advantage?  Do the tubes need to maximize the plate surface area for some reason?

I have not seen or used this particular tube before, so if the explanation has been given at some point in the past I will apologize for repeating the question.

Thanks in advance for any lore that can be passed along.  Yes, I did poke around on the web but I only see mentions of single and dual plate structures - but no functional explanations.

Best Regards,

William