[Milsurplus] Please Help ID WWII Russian Tube

[David Stinson]

I recently acquired a very neat WWII Russian aircraft radio- a "US-P."  The
tubes are Russian copies of
6K7, 6H6 and one which I cannot identify.
It looks like a metal 6SK7, and is in the circuit
were one would expect a mixer or pentagrid
converter.  If one were to look at the markings
in English, it would appear to say "6A7 VIII-61,"
but that is not correct.  The "A" is actually a Russian
letter and, in any event is certainly not a 6A7.
A drawing of the tube markings is at:
http://home.netcom.com/~arc5/russtube.bmp

Can anyone tell me the U.S. equivalent of
this tube?

Thanks!
73 Dave S.