Timekeeping in the former East Germany

Ruhla Sumatic

Ruhla Sumatic Travel Alarm Clocks


Gold Medal Winner Leipzig

International Trade Fair 1968

Ruhla Sumatic Travel Alarm Clocks - Close Up 2

Ruhla Sumatic Guidance

Ostalgieruhla – Ruhla Sumatic – guidance

The above link launches a pdf document which covers the following:

  1. Check your clock is complete
  2. Alarm Mechanism
  3. Problems with alarm
  4. Clock Mechanism
  5. Problems with Clock Mechanism
  6. Checking the Alarm contacts

Ruhla Sumatic – Electrical Circuit guidance

Ruhla Sumatic – guidance 3 – Contacts

Ruhla Sumatic Service ManualRuhla Sumatic Travel Alarm Clocks - Close Up 1

The information below is a translation of the Operation Manual included with a Ruhla Sumatic Travel Alarm on purchase (translation by Sekondtime, Ostalgieruhla Watches of the GDR)

Hear the Sumatic buzzer alarm

Click here to listen to a Ruhla Sumatic buzzer alarm.


The calibre 24-39 Sumatic Travel Alarm Clock contains a jewel less pin anchor escapement wristwatch movement. The small size, design and buzzer are an all new design. Compared to standard clocks the alarm clock is more versatile and characterised by a low operating noise. The electronic alarm buzzer will wake a normal person from sleep and is powered by a 1.5 volt cell battery with a normal temperature operating range of 36C to -3C.

 The clock case protects the clock from damage or exposure to water. Using the crown (1) wind every 24 hours. Use the crown also to wind the hands forwards or backwards. Rotate the lens (2) to turn the alarm time indicator (3) to the desired time. The alarm time indicator may be moved forwards or backwards. The alarm buzzer is equipped with one transistor and a printed circuit and should not be removed to avoid affecting its operation. The original battery (6) can be replaced when required. The positive terminal should be placed into the recess whilst the spring rests on the negative terminal.

The following batteries may be used: RZ 53 (SU), Mallory RM 625 and 625 mn, Everready 625, Varta 246 and similar cells with the same outer dimensions.

Also, the small battery B 80 from Hungary may be used or Type 9170.1 from VEB Elementebau Zwickau. Small batteries have a lower capacity than the o G. cells, but they can be charged with a suitable charger.

 A list of service centres can be found at every point of sale.

 The battery will last for 1 year with normal use.


How to remove the movement from a Ruhla Sumatic Alarm Travel Alarm

The following pdf guide shows a step by step photo guide for the removal of the UMF 24-39 Calibre movement from the Ruhla Sumatic Travel Alarm – Ruhla Sumatic – Movement Removal Guidance   (document may take a moment to download)


4 responses

  1. Gabriel

    Hola, me llamo Gabriel y soy de Asturias – España, tengo un reloj sumatic y tiene una pieza dañada, ¿donde podria conseguir repuestos?

    September 30, 2015 at 1:22 pm

    • Hola Gabriel,

      Gracias por su mensaje. Para adquirir piezas por un reloj Sumatic, lo único método es comprar un reloj antiguo y sacar la pieza.

      Pero, yo tengo unos antiguos relojes Sumatic desempleados. Quizas, tengo la pieza que busque vd. Envia me una photo de la pieza a mi email: sekondtime@gmail.com.


      October 1, 2015 at 11:12 am

  2. Omar

    Hola Alguien podría decirme que modelo de batería de botón lleva hoy día ? Desde ya gracias. Omar de Galicia

    December 18, 2015 at 1:32 am

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