[morzh]

Marty

Here goes.

Go to radiomuseum, for example, and see the tube, say, 6J5G. This is one of the tubes i have on 37-116.
http://www.radiomuseum.org/tubes/tube_6j5g.html

Now the way they list the pins on the picture is from the key CLOCKWISE Mass(GND)-F(filament)-A(Anode for Plate)-Empty-Grid-Empty-Filament-K(cathode).

Now let's go to my 116 diagram which lists the tubes' voltages with the pics of the sockets with pins' names.
The note says "Socket Voltages Measured from Underside of Chassis).
This means the pins are lookled at FROM THE BOTTOM.

Now the 6J5G pins go CLOCKWISE (from the bottom):
(unmarked) - F - Plate - (empty) - Grid - (empty) - F - K(cathode).

Now as you can see the pins listed (on the Radio Museum Site) are looked at FROM THE BOTTOM and they are CLOCKWISE.

Same pinout is given here

http://www.r-type.org/pdfs/6j5-2.pdf

PS. Again, I do not know for all tubes whether the convention applies.