ID: 
534
Maker's Name: 
AWA
Where made: 
Australia
Dimensions: 
2.8 × 2.8 × 10.5 cm

This valve has, in one envelope, two diodes and a pentode. It was used in domestic radio receivers.

The diodes were used to detect the audio from the IF frequency stage, and to provide a negative DC signal to control the gain of earlier stages (AGC).

The pentode was used as an IF amplifier, or the first audio stage.

This particular valve is marked D^D, which means it was manufactured for WWII defence purposes.