This transmitter and receivers were used in german tanks, like the "Tiger", Panther". Frequency covering 27,2 Mhz - 33,4 Mhz. The tubes in the receiver are RV12P4000. In the transmitter all RL12P35. Working conditions AM and CW. The power amplifier is a rotary transformer "U10E" for the transmitter and the" EUa" for the receiver. These items were build by SABA Germany.