Direction Finding DF Indicator of R.1155 Nav-Com System C-118 used to measure and indicate

used to measure and indicate to the pilot the altitude over the terrain during flight

The aircraft had a separate gyro horizon and vertical velocity indicator for routine flight monitoring

there is a locking screw that captures the rotating ring and preventing unintended rotation

but it is there and shows the matching serial #)

Direction Finding DF Indicator of R.1155 Nav-Com System C-118 used to measure and indicateHere is a WWII era Direction Finding (DF) Indicator as used in aircraft of the British Royal Air Force, such as bombers Avro Lancaster, Handley Page Halifax, and Vickers Wellington, and patrol bomber Short Sunderland. The DF Indicator received its signal from the R. 1155 receiver in the radio (wireless) compartment. By seeking a signal from a ground transmitter, the indicator displayed the direction of the transmitter in relation to the aircraft by