Multiple negative ground radios on a single power supply

Discussion in 'General Technical Questions and Answers' started by NQ8J, Sep 10, 2020.

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  1. WN1MB

    WN1MB XML Subscriber QRZ Page

    Right! Additionally, in a car that rolls around on four insulators!
    NQ8J likes this.
  2. NQ8J

    NQ8J Ham Member QRZ Page

    I've seen two RS-35A's and an RS-50A.that had an internal bonding jumper installed.
    Last edited: Sep 10, 2020
  3. NQ8J

    NQ8J Ham Member QRZ Page

    I started this thread to discuss what I'd call "unintentional" current flow in multi-radio setups on a single supply because of the negative-ground bond in the radios, but evidently everyone found it more interesting to focus on whether or not the negative-ground bond is installed at the power supply. LOL...
    N0TZU, KB0MNM and K7JEM like this.
  4. WR2E

    WR2E Ham Member QRZ Page

    Yep, hijacked by he who has an agenda and can't help himself. Only took one page too!
    N0TZU likes this.
  5. N0TZU

    N0TZU Platinum Subscriber Platinum Subscriber QRZ Page

    Well, I did ask you in post 23 if there was some problem you were trying to solve, since I don't have any problem in my shack with the return current flow not being confined exclusively to the negative supply lead. WB2WIK also said he didn't have a problem because of it.
  6. KB0MNM

    KB0MNM Ham Member QRZ Page

    Late note: Both links are good- in the Grounding and Audio.pdf, see pages 141 to 145 for pertainent info, this thread, re: Power supply bonding to negative D.C.(bad)- some Astrons.
    Please remember that this is an older article (2015), and I have no financial interest in Astron(TM/R/Etc.) nor problem with their product(s).
    NQ8J likes this.
  7. WA7ARK

    WA7ARK Ham Member QRZ Page

    All of this discussion results because all 14V DC-powered ham transceivers and accessories have their black DC power wire connected to their chassis as is the threaded part of their SO-239 coax connector.

    Ergo, it is impossible to separate DC ground from RF ground from AC ground from(assuming there is a AC-line powered supply in there somewhere) and from my metal building, no matter how many pictures Derrick posts...
    Last edited: Sep 10, 2020
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  8. KB0MNM

    KB0MNM Ham Member QRZ Page

    So what happens if the Polyphaser(tm/R/etc.) on the bulkhead does not pass D.C.? I have no financial interest in Polyphaser(TM/R/etc.) yet note that some do affect S.W.R. readings if seen from the wrong ( radio ) side of the 'protector module'.
  9. AA4PB

    AA4PB Ham Member QRZ Page

    In my case, the power supply and all of the radios are mounted in a steel rack console so all the chassis are connected together by the steel rack. Cutting the jumper in the power supply wouldn't do anything unless I insulated everything from the rack. I've never had any issue with everything being connected together. I have each piece of equipment connected via a copper strap to the steel rack just to make sure all connections are secure and not dependent on mounting bolts. I question the safety of different pieces of equipment, all within reach of the operator, being tied to different grounding systems.
    W9WQA likes this.
  10. K7JEM

    K7JEM Ham Member QRZ Page

    The DC is being passed on the shield of the coax, so it doesn't matter what kind of continuity you have on the center conductor.
    KB0MNM and N0TZU like this.

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