Gents GENTS C7 master / transmitter tips & info

Discussion in 'Electric Horology' started by bruce linde, Jan 9, 2019.

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  1. bruce linde

    bruce linde Technical Admin
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    #1 bruce linde, Jan 9, 2019
    Last edited: Jan 10, 2019
    just got this... it came with a 'gents of leicester controlled electric clock system' .pdf pieced together off of the message board.

    i'd like to know how to get it running... what should i know? what do i need?

    i did find this post, as well: Gents C7 - adding a C69 Bell controller


    gent_master_clock.jpg gledhill_2.jpg gledhill_3.jpg gledhill_4.jpg
     
  2. bruce linde

    bruce linde Technical Admin
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    #2 bruce linde, Jan 10, 2019
    Last edited: Jan 11, 2019
    here's essential documentation:

    Instructions - Gents C7 Transmitter.pdf
     

    Attached Files:

  3. bruce linde

    bruce linde Technical Admin
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    for some reason i thought this was going to be difficult, but it couldn't have been easier.

    i tried the 6v power supply i had purchased from kensclockclinic for my stromberg master clock but it did not stir the slumbering beast. i found a 12v power supply in the garage and hooked it up: we had lift-off! :cool:

    i reached out to tinker dwight, who walked me through ohm's law to figure out how to set the variable resistor on the left.

    amperes times resistance is equal to the voltage... I * R = E
    which can be moved around to resistance equals voltage/amperes... R = E / I
    desired amperes for the clock is .22, so 12v / .22 = 54.5 ohms​

    i put a wire between the two power terminals and used my fluke voltmeter to dial in 55 ohms across the contacts using the sliding resistor on the left.

    i then cleaned the contacts, escape wheel surfaces and other parts that interact when running, and it's been running ever since:

    main -

    secondary -


    p.s.: love that they call it a 'transmitter' instead of a master clock:

    latch_plate.jpg clean.jpg

    p.p.s.: the pendulum assembly weighs in at 11 lbs
     
  4. bruce linde

    bruce linde Technical Admin
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    #4 bruce linde, Jan 12, 2019
    Last edited: Feb 2, 2019
    also found this really good installation/maintenance/repair guide... hope it helps someone.

    a 4-page .pdf with enlarged versions of the annotated drawings in the document added 2/2/19.

    pul-syn-etic_repair_maintenance.pdf

    gent_C7_illustrations.pdf
     

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  5. bruce linde

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  6. bruce linde

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    #6 bruce linde, Jan 16, 2019
    Last edited: Jan 17, 2019
    more docs:

    - a gent catalog from 1925
    - a gent brochure from march 1905
    - a gent instruction manual from 1970

    gent_brochure_march_1905.pdf Gents installation manual.pdf GentCatalog1925.pdf
     

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  7. bruce linde

    bruce linde Technical Admin
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    #7 bruce linde, Jan 18, 2019
    Last edited: Jan 21, 2019
    there was a Gents Master Clock Survey being circulated by the electric horology sub-group of the AHS (antiquarian horological society) in london. please see this thread for the .pdf survey: Gents - Gents Master Clock Survey
     
  8. bruce linde

    bruce linde Technical Admin
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    an early brochure... note the promised accuracy with the optional upgrade invar pendulum...

    IMG_1310.JPG
     
  9. harold

    harold Registered User
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    I am about to trade for one of these. Can you show me where to hook up to the power points.
     
  10. bruce linde

    bruce linde Technical Admin
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    if the one you're getting is like mine, refer to the last photo in my post #3 above... it shows the hookup terminals and the variable resistor.

    the resistance should be about 55 ohms for a 12V supply. connect the two terminals with a temporary wire across the the cabinet... do not have the supply connected for this measurement. measure across the open points (follow the left arrow from the 'clean me!' legend... with you meter set on ohms. the 100 ohm variable resistor ( lower left ) might have a set screw that holds it in place.

    ohms law says I * R = E (also written as A * R = V (ampere * resistance = volta ('ampere' and 'volta' being the scientists who worked this out))). amperage times resistance is equal to the voltage. with a 12v power source and a target of 0.22 amperes (specified in the pul-syn-etic docs and the label inside the clocks) you can move the equation around to R / E = I or R = E / I or 12/0.22 = 54.5454... or close enough 55 ohms.

    i have a slave/secondary clock winging its way to me and will have to re-do the math for mine when it arrives and i hook it up.

    (thanks and acknowledgement to tinker dwight for walking me through this...)
     
  11. bruce linde

    bruce linde Technical Admin
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    some pictures from a 1905 Gents catalogue: water-level indicators

    IMG_7167.JPG IMG_7169.JPG IMG_7170.JPG IMG_7172.JPG IMG_7173.JPG IMG_7174.JPG
     

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