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Bad Bird?

Discussion in 'General Technical Questions and Answers' started by W3DAB, Sep 6, 2018.

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  1. W3DAB

    W3DAB Ham Member QRZ Page

    I have a Bird 43 and a 1000H slug purchased used separately. The needle barely moves when pushing ~500W through it. I want to figure out if the issue is with a meter or with the slug so I know which to ask for a refund on.

    (1) I get zero ohms from contacts where you plug the slug in to all the way to the meter movement connections. I have cleaned all contacts as well. That just leaves the meter movement. How do you know if a meter movement in a Bird is good/bad?

    (2) How about a slug? I have read that you can check a slug like you would a diode, but I'm getting continuity in both directions (only less on the other direction).

    Thanks!
     
  2. W9GB

    W9GB Ham Member QRZ Page

  3. AB3TQ

    AB3TQ Subscriber QRZ Page

    You cleaned the contacts on both sides of the slug with an eraser?

    You have a Bird Meter and ONE slug? But you are familiar with the function of a Bird? I have to wonder, you do know the slug can be oriented in two directions? In the Reflected Power direction into a good dummy load you would only see limited meter movement. Just pointing out the most basic thought I had when reading your post.

    If you had a known good slug you could determine the status (good or bad) of the meter. Do you know anyone nearby that has a good Bird Meter? With a known good slug and meter you could easily diagnose this.
     
  4. CX3CP

    CX3CP Ham Member QRZ Page

    The slug impedance of contacts is definitely high impedance, if you measure both with the ohm meter you will found at list 26k ohms in one direction and maybe much more if swap the tips. So, zero ohms or shorted is a bad signal !
    And for the meter you must found an impedance of approx 5K ohms.

    hope this help !!!
     
  5. W3DAB

    W3DAB Ham Member QRZ Page

    Thanks for all the replies. Yes, I am well aware that one direction reads fwd and one direction reads rev (SWR). I cleaned the contacts with electronics cleaner and the "finger" contact on the inside is position/tensioned correctly and all clean. I do not have another slug or a nearby friend with another meter which is why I post the questions here. I don't feel comfortable banging the slug as suggested in the video as a troubleshooting method though.

    I will check the resistance of the slug again to see what it is actually reading and report back. I did not read zero ohms or open though thankfully. I will also measure the resistance of the meter movement and report how close it is to 5K ohms. Thank you all!
     
  6. CX3CP

    CX3CP Ham Member QRZ Page

    I found this, could help you to clarify the situation.

    [​IMG]
     
  7. W6KCS

    W6KCS Ham Member QRZ Page

    One problem that is hard to find is where the coax center conductor makes the connection in the plug that plugs into the casting. IIRC it's a spring that holds the center conductor. Try cleaning that if you don't find anything else.
     
  8. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    Be careful "measuring" the meter.

    It's a very sensitive meter, 30uA full scale, and if you accidentally try to measure it on a lower resistance scale you can burn the meter out. I place a resistor in series with the Ohmmeter leads to limit current and prevent meter failure due to testing.
     
  9. W3DAB

    W3DAB Ham Member QRZ Page

    KCS, I have nearly zero ohms from meter connections to "finger" contact that contacts the slug so I am ruling out the connector. I will check resistance between the shield and center conductor of the coax when I disconnect the meter movement form the coax to test it.

    Thanks WIK, I will take precaution of the meter movement when testing.

    CP, that diagram is quite helpful! I did see this and, using it, I am feeling that the issue is either my slug or the meter movement itself. This is why I want to try to figure out the best definitive way to verify the slug and the meter movement without the luxury of having another meter or slug or friend with one of them to compare. Since I have cleaned and reinstalled the DC connector, cleaned the line section and all removable parts (finger contact, SO-239s), and meter movement posts, then tested resistance the whole path all the way to the meter movement posts, I am pretty sure the issue is either the slug or the meter movement. I want to figure it out so I can ask for a refund in time for the defective part (Bird 43 or slug).
     
  10. NH7RO

    NH7RO Ham Member QRZ Page

    Expected to see a thread about a foul-mouthed parrot here. Oh, well, maybe "Bad Slug" might have been more apt.
     
    AC8UN likes this.

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