STR Morse training equipment, „Creed Morse transmitter“; manufactured by STR / Zellweger, Uster.

In the late 1940s, the companies Standard Telephon Radio and Zellweger, Uster, put together Morse code training equipment consisting of a paper tape punch and a Morse code transmitter converting punched paper tapes into morse code for use in Morse code training.

• Principle:
  • Punched paper tape reader / morse code transmitter
  • Hand punch
  • Power supply unit (Zellweger AG)

• Mains operation

The Creed Morse transmitter system was probably used for telegraphy training in the Swiss army from the 1940s onwards, more detailed information is missing.

The system consists of a paper tape perforator, which is first used to create a perforated paper tape with the text to be sent.

The motor speed and therefore the paper tape speed is controlled by a centrifugal governor, the punching head is used to punch the holes and the tape is then moved on by the transport head. Transport holes are created in the centre of the paper tape, these are also punched when the space bar is pressed (for a word space). To encode a dot, two holes are punched at the same level on both sides of the transport hole; to encode a dash, the two holes on the sides of the transport hole are punched one step apart.

In the morse code transmitter, the punched paper tape is inserted so that the second hole of a Morse „dash“ is directed to the front, in the documentation it is recommended to mark the start of the papere tape with an arrow when creating it.

The perforated paper tape is pulled through the encoder & transport head with the transport holes. The polarised telegraph relay picks up when the rear contact pin in the encoder head makes contact; if a second hole is at the same level (in the case of a Morse „dot“), the relay receives a cut-off current impulse. In the case of a „dash“, the relay picks up when contact is made in the rear contact pin, the transport step takes place in the following period and the telegraph relay only picks up again when the front contact pin makes contact in the offset hole (in the case of a Morse code „dash“), the dash therefore lasts exactly three times as long as the dot with three half-periods.

I am very interested in pictures, further documentation and information about what this set was used for.

Papaer tapes prepared with the tape punch are converted into Morse code in the morse code transmitter.

• Two AC2 tubes and one AZ1 rectifier in the power supply unit.

The Morse code transmitter system „Creed“ was used for Morse training lessons and for taking the Morse code exams, mandatory for all signalmen. I would be grateful for further information.