Home:  Exchange Equipment: PO WALL CLOCK, 1970's


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Slave units used in Telephone Exchanges and also in Post Offices for many years, these were driven by a master long case clock situated in the Exchange.

See Item A0073

Your comments:

  • I have number of these running with an electronic pulser using mains 50 hz as the clock signal to the divider chain. I also have a clock which looks identical but uses a synchronous motor. Lovely clocks.
    .......... Roger cawley, Hemel hempstead, 6th of January 2024

  • The clock pulse supply from the exchange master clock would often go to other public buildings in the area. In Dulwich in SE London it fed local schools, the public library and I think the Horniman Museum.
    .......... Paul Stewart, London, 10th of December 2023

  • Worked as a PO Engineer in a large sorting office late 70's and the time changes back and forwards for daylight saving always raised a smile. Went down to the master clock in the basement and either stopped the pulses for an hour, or advanced all the clocks quickly by hand pulsing. If the clocks went forward you could hear about 300 people on night shift cheering, going backwards was a lot of load moans.
    .......... John Walley, Newcastle upon Tyne, 11th of October 2020

  • We called these Pulse Clocks. They were driven by a pulse from the Master which was housed in a case about a metre tall with a glass front and long pendulum with infinite mechanical adjustment as I recall (fingers crossed!) The mechanism was great to watch as it gradually brought two brass tips together to trigger a relay and send the next pulse. I fitted many of these in our main exchanges in the North East.
    .......... Terry Kirkup, Newcastle upon Tyne, 28th of July 2014

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