Ham IV Rotor Control Box Troubleshooting

Discussion in 'General Electronics Chat' started by tracecom, Jun 14, 2016.

  1. tracecom

    Thread Starter AAC Fanatic!

    Apr 16, 2010
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    I have a Ham IV rotor that was on a tower that was struck by lightning several years ago. I am trying to repair it, and am starting on the control box, which is disconnected from the rotator. A schematic diagram is shown below.

    There is no apparent damage to the control box except that both fuses were open. I removed them, and put in a new AGC 5 in the F2 position; it blew as soon as I turned on switch S1. If I am reading the schematic correctly, S3 (N.O.) prevents current flow through the power transformer, therefore I suppose the first problem to be in the regulator circuit inside the dashed lines. What is the logical progression of things to check? Thanks.
    Ham IV Rotor Schematic.JPG
     
    Last edited: Jun 14, 2016
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    S1 powers the primary of the transformer marked meter, I would suspect any thing on the DC power circuit, try disconnecting the secondary first and test any diodes or rectifiers on the output side.
    Max.
     
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  3. tracecom

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    Apr 16, 2010
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    OK, CR1 was open, and VR1 was shorted. I replaced them both, the bulb lights, the fuse blowing has stopped and I measure 13.48V across the zener. Progress!
     
  4. tracecom

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    Connected the rotator; all works. Hooray!
     
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  5. GopherT

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    Nov 23, 2012
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    One less rotor controller in a landfill!
     
  6. tracecom

    Thread Starter AAC Fanatic!

    Apr 16, 2010
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    And about $300 in my pocket when I sell it.
     
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