New bridge ground question

Discussion in 'Luthier's Corner' started by Clarence001, Apr 21, 2020.

  1. Clarence001

    Clarence001 New Member

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    Hi All,

    This is a continuation of my last question (http://www.everythingsg.com/threads/grounding-questions.36803/) but it's a bit of a new question regarding grounding the bridge.

    As was discovered in the last thread, my guitar has custom bridge posts because of the bigsby and roller bridge (assuming this done from previous owner, pic 1). There is a bare wire in the control cavity (pic 2), and I thought it was the bridge ground. I did a continuity test between the posts and the wire, and there's none. If there is none, what is the best way to ground the bridge? Via copper tape extension from pickup cavity? Other ideas? Or is this something I shouldn't be concerned about? If this bare wire isn't continuous with the bridge, what is it's function and should it be ground on the volume pot as originally configured (pic 3)? Or is it useless and should be removed?

    Thanks in advance for any help!

    03_front.jpg 04_back.jpg
    SGjr_pots_orig.jpg
     
  2. donepearce

    donepearce Well-Known Member

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    On the original guitar it grounded the nearest bridge post. It will have done that by being squashed between the bush insert and the wood. It sounds like that is no longer the case, so you need to remove the threaded rod and drill through that dowel sideways with a fine drill to connect with the original hole carrying the wire. Then you can put a new wire through to connect the bridge post to ground. Good luck.
     
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  3. smitty_p

    smitty_p Well-Known Member

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    Have you tried a continuity test from the Bigsby to the ground wire?

    On my 1974 Gibson SG with a stock Bigsby, the ground wire does not contact a bridge post. The wire is sandwiched between the underside of the Bigbsy frame and the body. Thus, the Bigsby frame is the grounding point, not the bridge. The effect is the same, however.

    As it appears the bridge is not original, and the Bigsby likely isn't either, the previous owner may have run the ground wire to the underside of the Bigsby the same way Gibson has done with Bigsby-equipped guitars.
     
    Last edited: Apr 22, 2020
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  4. Clarence001

    Clarence001 New Member

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    Smitty P you are my hero! there is continuity with the Bigsby and the wire. I thought I had checked it originally with no response, but after everyone's replies I did a real thorough check and the Bigsby is grounded. Thank you so much!
     
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  5. Clarence001

    Clarence001 New Member

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    Thanks donepearce for your previous answers and following up on this post. I think I got lucky, Bigsby is grounded. Was not looking forward to randomly drilling the body looking for that wire...Great info to have though, many thanks.
     
  6. donepearce

    donepearce Well-Known Member

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    That's great. Even better, you now have the freedom to fit a nylon saddle bridge if the fancy takes you without losing your ground.
     
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  7. smitty_p

    smitty_p Well-Known Member

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    Terrific!

    That's good news.
     
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