Swedish type Ra 121B
The Ra 121B was a vehicle mounted VHF FM radio. The set is connected to the vehicle antenna via a coaxial cable. It is basically similar to the Ra120 and Ra122 but having a different power supply unit. Note that the function of the Calibrator knob is incorporated in an existing switch
Detail picture of transmitter RF amplifier tank coil with screening plates removed, showing push-pull configuration. The antenna coupling coil (in the centre, coloured red) may be adjusted by means of a slider
Ra121B with chassis opened for inspection or service
The power supply unit may be removed from the set as a complete plug-in assembly. Note the use of an early Delco type 2N277 power transistor (along with a type OC140 transistor) in the LT voltage regulator circuit