Sensibly equivalent¶ to:
1P10 2P2 3S4 CV820 CV2370 N17 VT-174
The DL92 is an audio output pentode valve designed for battery portable broadcast radio receivers in the latter part of the 1940's. The output power is very small so either a high efficiency loud speaker would be used or headphones.
The picture above gives a clearer view of the lettering on the envelope. This shows it to be an import from Philips and badged as Mullard.
The thin glass tube envelope is 17 mm in diameter and excluding the B7G base pins it is 46 mm in length.
References: Datasheet & 1040. Type DL92 was first introduced in 1947.
Absolute Maximum Operating Conditions¶
Updated January 27, 2013. shape:thin.glass.tube construction:all.glass type:pentode age:1940.1950 base:b7g heater:1.4v pins:7 pin:1.f pin:2.a pin:3.g1 pin:4.g2 pin:5.hct.g3 pin:6.a pin:7.f+