Sensibly equivalent¶ to:
5687WA 5687WB CK5687 CV2578
The 5687 is a special quality double triode. It is described as a general purpose medium gain triode pair with good emission. The pair can dissipate 7.5 Watts or a single triode can dissipate 4.2 Watts.
The picture clearly shows the pair of flat cathodes at the top, with the copper grid supports either side of each cathode. The anodes are shaped and blackened.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 45 mm tall.
References: Data-sheet & 3002. Type 5687 was first introduced in 1956.
Absolute Maximum Operating Conditions¶
Updated April 26, 2016. shape:thin.glass.tube construction:all.glass type:double.triode age:1950.1960 base:b9a heater:6.3v pins:9 pin:1.a pin:2.g1 pin:3.k pin:4.h pin:5.h pin:6.k pin:7.g1 pin:8.hct pin:9.a