Easy ground-plane for the shack to reduce RFI

Discussion in 'Tips and Tricks' started by W4PG, Oct 29, 2021.

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  1. W4PG

    W4PG Super Moderator Lifetime Member 279 Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    If you're having problems with RFI in the shack and have tried all the toroids you can find and are still having trouble you might try this. The excellent book "Grounding and Bonding for the Radio Amateur" recommends putting your shack equipment on top of a ground plane. 50 years a ham and I have never tried this but seems reasonable.

    The ARRL book suggests getting copper flashing used in building construction but I found these copper plates on Amazon pretty cheap and they are very easy to work with and very sturdy. Just search for "CynKen copper" and you will find several different sizes. The ones I have are 300 mm by 300 mm and 0.5 mm thick. They are very easy to cut with some tin-shears. Drill a small hole and hook it up to your shack ground. The pointed edges are very sharp so I trimmed them slightly to reduce the risk of cutting myself. IMG_6354.JPG IMG_6355.JPG
     
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  2. WA7ARK

    WA7ARK Ham Member QRZ Page

    ...and I predict that doing this will not do any thing useful to reduce RFI, but it will make it more likely that you will get electrocuted!
     
    W9WQA, N1IPU, K3EY and 4 others like this.
  3. PU2OZT

    PU2OZT Ham Member QRZ Page

    It's not new. Read on a QST issue, that very year (couple years ago) I was an ARRL subscriber.

    To the OP, you'll need, at least, two connections, or there is something I'm missing.
    Electric copper sheets cost an arm and a leg in Brazil.

    Oliver
     
  4. N2UHC

    N2UHC Ham Member QRZ Page

    Are you kidding? Copper is the new miracle material nowadays, if all the copper-infused arm bands, knee braces, and now even covid masks are any indication. Obviously it will magically make RFI disappear.

    Personally I just spray a little RFI eradicator on my antennas and never have a problem. You can find it at auto parts stores next to the turn signal fluid.
     
    WA8FOZ and N0TZU like this.
  5. K7TRF

    K7TRF Premium Subscriber QRZ Page

    It's not new but it's still a bit of ham mythology.

    Most of my rigs have metal cases that are grounded. Even my newer rigs with plastic cases have an RF shield inside that's also grounded. Adding a grounded piece of copper a couple of cm below the already grounded shielding won't really do anything.

    This is another spin on the whole station grounding for RFI reduction thing. There are good reasons to ground gear like human safety for equipment running on AC mains or grounding coax shields before they enter the building but grounding for RFI reduction reasons is at best a band aid. If grounding rigs in the shack reduces RFI then there's a problem with the antenna system that should be solved with better antenna designs or common mode choking outside of the shack and not by grounding your rigs.

    This copper plate idea (which has been floating around for many years) is similar. If it actually does something then there's an issue somewhere else that should really be resolved. I suppose if someone runs commercial or homebrew equipment that has no shielding around sensitive RF or IF components then sure a grounded shield could help but the better answer would be to enclose the gear in a conductive enclosure and ground that instead of adding a conductive plate below the gear.
     
    Last edited: Nov 1, 2021
    N0TZU and PU2OZT like this.
  6. KK4OBI

    KK4OBI Ham Member QRZ Page

    Use this plate when soldering. Attach a wrist grounding strap. If critical components , wear a grounded smock. Copper plated aluminum sheets from hardware stores cost less.
     
    W9WQA and PU2OZT like this.
  7. K3EY

    K3EY Premium Subscriber QRZ Page

    Did it do anything? I bet you it didn’t do anything…am I wrong?
     
  8. W4PG

    W4PG Super Moderator Lifetime Member 279 Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    I did this in a brand new shack at my new 2nd home. I have not had any RFI issues so far but didn't have any before. It's a bit easier to add the plates at the get-go than place them after everything is already in place. They are pretty cheap and easy so I figured "what the heck."

    RFI in the shack is usually a result of some other issue that needs correcting as many pointed out, and I agree. As I mentioned in the OP, if you have tried everything else and STILL have problems, this might be worth a try. It's cheap and easy so no harm.

    I'm a bit leery of it as well and wonder about the effectiveness but I've seen this suggested in a couple of grounding and RFI books including the ARRL one on grounding. DX Engineering sells their own (rather expensive) version. I have a bit of RFI issue in my main shack in FL when I point my beam right over my shack and run high power on 15 meters. Computer mouse starts seeing cats and running around randomly doing crazy stuff and not otherwise working correctly. It's a wireless mouse so pick what-ever cable one might put some toroids on and I've done them all. It doesn't happen when I beam the other way so just a strong local RF field playing with the computer I'm guessing.

    Maybe I should put a copper floor and ceiling in the shack and ground that?? :eek:
     
  9. K3EY

    K3EY Premium Subscriber QRZ Page

    I learned long ago grounding issues are not an exact Science. I used to have RFI issues until I ponded four different 10 foot cooper ground rods straight into the ground at different locations and tied two of them together with number 4 copper wire. That helped a great deal but what completely eliminated it was selling my amplifiers. For the last decade or so I have only run between 5 and 30 W with 100 W being the max and seldom at that.
     
  10. WZ7U

    WZ7U Ham Member QRZ Page

    Why not? It seems to work for the MRI folks down at the diagnostic imaging center.
     
    K0UO likes this.

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