The 15 W. S. E. b was first built by Telefunken in 1939 along with the 15 W. S. E. a. The primary difference between the two, was the capability of the "b" model for teletype transmissions with the Feldfernschreiber (Hell Schreiber). The power requirements for these device were rather complex as indicated below.

The 15 W. S. E. b was a popular device for communications teams at divisional headquarters. Erwin Rommel, commander of the Afrikakorps, used this trasceiver with the Hellschreiber to communicate with Berlin. In the 2005 German film Downfall, It is seen in the radio room of the Führerbunker operated by Roschius Misch (the bunker radio operator).

The 15 W. S. E. b consists of a transmitter-receiver with combined operating panel housed in one container, two power supplies, antennas and remote control unit. Frequency adjustment is common to transmitter and receiver which are always on the same frequancy. Receiver fine tuning must always be done by knob "Empfänger-Nachstimmung" (Receiver fine tuning) never by knob "Frequenzeinstellung" (Frequency setting). When tuning the transmitter either inthe "Tg" or "Tn" position, the transmitter must be first excited by pressing either the key of the microphone button. When transmission is of long duration, the operating switch should be set to "Senden TG" for CW or to "Senden TN" for voice. This is done to save current by shutting off the receiver. Likewise, during long periods of reception, the transmitter can be shut down by setting the operating switch to "Empfang Tn" or "Empfang Tg". As a security measure, it is possible to tune the antenna without causing it to radiate.