NASA Project Mercury Encryption

This is the KY-171 Audio Frequency Coder used for the NASA Mercury Project (1958-1963) to encode radio traffic between ground stations, and ground stations and the space capsule. It is used with the T-560B Radio Transmitter to send encoded telemetry data. The transmitter bypassed the coder when used for emergency voice backup. The R-669A Radio Receiver is paired with a KY-172 Audio Frequency Decoder and the C-1669 Coder Control to decipher the messages. All of these devices are part of the AN/FRW-2 Radio Set.