This is the electronic assembly from an engineering test model of the approach radar set used to land on the moon. This signal processor was mounted in the equipment bay of the Apollo program lunar module (LM). The lander was equipped with a continuous wave doppler radar set that controlled the powered landing. This instrument provided velocity, slant and altitude measurement data to the guidance computer used to manage the rocket that slowed the descent of the LM. The radar set was manufactured by the Teledyne Corporation. This electronics box and the antenna (A 19740641000) were transferred to NASM from NASA's Johnson Space Flight center in 1974.