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Surge Absorber Troubleshooting

Discussion in 'Radio Circuits, Repair & Performance' started by K5RWD, Jan 7, 2019.

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  1. K5RWD

    K5RWD Premium Subscriber QRZ Page

    Good evening,

    I am troubleshooting an FT-1000 transceiver and I have come across a glass Surge Absorber (DSA-301LA) and I am wondering if anyone knows how to troubleshoot this device. My first guess is that it's a type of diode but I can't find the proper information on how to check it. I ran a diode tester and resistance test on it and both showed totally open, no readings at all.

    I would be very grateful if anyone could provide some insight to this.


  2. CX3CP

    CX3CP Ham Member QRZ Page

    I never put one of these arrester to test, although I think it might be some way, but by now you can only check that it has not been fired before, eg check for shorted, seem burned internally and/or measure some resistance, then there is no way to test its operation.

    The only way to try a firework is launch it.
  3. KA5IPF

    KA5IPF Ham Member QRZ Page

    Look at the element in it. If one solid color, dark, and there is no discoloration to the interior glass it's probably OK. If the element has a yellow line around it then it has fired and should be replaced. Same for discolored glass.
  4. W7UUU

    W7UUU Principal Moderator Lifetime Member 133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    Here's a datasheet on it, if that helps:

  5. K7TRF

    K7TRF Premium Subscriber QRZ Page

    It should read as an open circuit until it fires and then it should provide a low impedance shunt to ground. If you're reading an open circuit across the surge suppressor then it isn't causing a problem in your circuit. It may have previously fired as Clif suggests in which case it will look dark or yellow through the glass. If that's the case then it's best to replace it so that you have protection against future surge events but if it reads open circuit it isn't currently dragging your system down.

    Similarly since these devices work by shunting surge events to ground you could temporarily lift one end of the suppressor to double check that it isn't shunting your signal. If nothing changes in your rig's behavior with one end of the suppressor lifted out of circuit then the suppressor isn't the root of your troubles.
  6. WA7ARK

    WA7ARK Ham Member QRZ Page

    15seconds on my Tektronix 576 Curve Tracer would answer the question...
    WB4SPT likes this.
  7. WB4SPT

    WB4SPT Ham Member QRZ Page

    With a very impressive 1500V max source, I might add. :)
    WA7ARK likes this.
  8. WA7ARK

    WA7ARK Ham Member QRZ Page

    And I have tested it by accidentally coming in contact with it...
  9. N1OOQ

    N1OOQ Ham Member QRZ Page

    Looks like it might be the GDT type... Gas discharge tube. If so, it should read open at low voltage, as a few mentioned above.
  10. K5RWD

    K5RWD Premium Subscriber QRZ Page

    Okay, thanks for all of your inputs. You provided the answers I kind of figured I would get.


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