V247C/1K "Heil tube". This measures 67mm overall length by 19mm wide (32mm across the copper disc). The base is B7G.
There are no markings on the valve to indicate what it is. However inside part of the structure is marked "2J A", and the number '47' is stamped on the lower part of the copper section.
More detailed images of this valve can be found here.
(more on Heil Tubes)
Another of the valves, this time with markings. This one carries the serial number 3SR internally.
This file was last modified
15:54:31, Tuesday September 02, 2014