On offer today a very nice device, 18mm anode, factory code I61 B7J with slightly smudged old shield print. On test each section gave the following results at Va = 250V Vg = -8.5V
Section 1: Ia = 14 mA; gm = 2.3 mA/V
Section 2: Ia = 14 mA; gm = 2.3 mA/V
The specification for a new/100% emission valve is:
Ia =10.5 mA; gm = 2.2 mA/V
As you can see, these results show a device which exceeds 100% EMISSION specification with extremely good matching of each triode section within each valve envelope.