Another unknown tube

[rotaspec]

OK, so among a large collection of tubes i just bought was this one. The bottle size is the same as 6F6G, it has the same connections, but the plate structures are much bigger. It test very much like a 6L6G on my Avo tester, but all the 6L6G's I have seen are in a bigger bottle. The distance between the mica's is about 1.5" (38mm).
Test figures: Vp=Vs=250v, Vg=-16.5v, Ip=46mA, gm=4.2mA/v
Anybody know what it is?

Sorry for the awful pics that my old camera takes this close.

Thanks in advance, Gary

 

[rotaspec]

Trying again with the pics

 

[radiotron]

looks like a 6L6GA, same as 19W 6L6 or 6L6G, stuffed into a ST-14 bulb, your transconductance measurement would seem to agree with that

 

[radiostar]

Size and shape is similar to National 6L6G, but National has slightly different top mica spacer. You need to take photo of top and getter.