Sensibly equivalent¶ to:
The NF2 is an HF pentode on a Ct8 base and designed for use on series heater chains.
The reverse carries the BAL716 stamp showing that it was made to the German Luftwaffe standard and inspected at that particular office. All equipment made for the Wehrmacht had such a proof mark. RLM stands for Reich Luftfahrt Ministerium and was used from 1933 to 1945. The code 12 39 is probably the date code.
The classic envelope is 38 mm in diameter, and excluding the Ct8 base pins is 100 mm tall.
References: Data-sheet & 3002. Type NF2 was first introduced in 1935.
Absolute Maximum Operating Conditions¶
Updated March 12, 2014. shape:classic construction:pinch type:pentode age:1930.1940 base:ct8 heater:200ma pins:8 pin:1.m pin:2.h pin:3.h pin:4.k pin:5.g3 pin:6.- pin:7.g2 pin:8.a pin:tc.g1