R-2A/APR-3 sonobuoy receiver

A R-2A/APR-3 Sonobuoy receiver. These receivers were used by allied patrol aircraft over the atlantic to pick up signals from the AN/CRT-1 sonobuoys dropped into the ocean to listen for German U-boats. The colour coding on the buoys correspondents to the colour coding on the frequency scale, so when a pattern of different coloured buoys is deployed it is easy to tune to the different buoys. the receiver is lacking it's outer casing and some minor parts. An accompanying AN/CRT-1 sonobuoy is avaiable in a separate listing.