[RFI] 80 meter RF getting into Ubee fiber 6E gateway causing loss of Internet

[David Eckhardt]

Jim, they'll never get it or learn.  I've given up......

Dave - WØLEV

On Mon, Dec 8, 2025 at 4:08 AM Jim Brown <jim at audiosystemsgroup.com> wrote:

> On 12/7/2025 4:46 PM, David Decoons wrote:
> > Hi All,
> >
> > This had been working fine for well over a year and just started a week
> ago.
>
> Many years ago, I had a gig driving around Chicago fixing sound and
> video problems, often in complex systems. When something stopped working
> that had long performed just fine, the first question to ask is "What
> has changed?"  Called to fix the sound system at Wrigley Field, the
> first question I asked was "what work has been done around the park
> recently?" and start looking for problems in wiring there.
>
> In other situations, think about what might have failed in your station,
> both in the shack and your antenna system. One thing that comes to mind
> is common mode current in the feedline caused by some form of imbalance
> in the antenna, the feedline, and matching on either end.
>
> That common mode current makes the feedline part of the antenna. That's
> why a serious common mode choke is needed at the feedpoint of our
> antennas. But antennas like yours cannot be effectively choked.
>
> > New issue popped up where RF out on 80 meters (about 1000 watts) into an
> "optimized" G5RV is causing the fiber gateway (Ubee WiFi 6E) to lose
> Internet connection and go into a reset condition after the RFis no longer
> present.
> > The antenna is about 60 feet from the fiber gateway. Ladder line goes
> into coax (no balun), then 50 feet of LMR400 Times Microwave coax to my 2x8
> 4O3A Antenna Genius.
> >
> > Antenna Genius, Tuner Genius, Power Genius and Flex radio all in a
> server cabinet in the garage 1 floor below the fiber gateway. Everything in
> cabinet ground to a copper buss then #2 to ground rod about 12 feet away.
>
> So any common mode current on the feedline is going to light up that
> gateway.
> >
> > Network cable from Ubee fiber gateway to Asus mesh router is wrapped 6
> times through a 2.4" mix 75 ring (F240-75) with no turns overlapping. Power
> cable to Ubee fiber gateway has 4 wraps through mix 75 wall wart ring.
>
> Wrong ferrite material for HF. The ONLY ferrite material suitable for HF
> is Fair-Rite #31. See the very specific designs on my website,
> k9yc.com/publish.htm  for transmitting chokes, and use them for chokes
> to protect equipment. Chokes should be on every cable connected to the
> gateway and the router.
>
> > I have had the Asus main mesh unit as the roiuter with the fiber gateway
> in bridge mode but have tried setting the Mesh system into access point
> mode and using the Ubee as the router, same results.
> >
> > I do have a Balun Design 1115d 1:1 isolation choke I could put in the
> coax line either where it transitions to 450 Ohm ladder line or at the
> antenna switch but my feeling is this may be brute force RF getting into
> the Ubee gateway.
>
> That's the least effective spot to kill common mode current. Further,
> with the extreme mismatch in your antenna system, any product that did
> anything useful would be frying. I don't consider any of these products
> to be doing anything useful.
>
> While you're on my website, download and study my tutorial on Grounding
> and Bonding. And buy a copy of the N0AX ARRL book on the topic, to which
> I contributed extensively.  Make sure that you get the Second Edition,
> which added material on what to do about grounding and bonding antennas
> for electrical safety, and which also makes problems like yours less
> likely.
>
> The earth is not a sump into which RF problems are poured. It's ONLY
> functions in a station are 1) Lightning protection; and 2) an essential
> part of some directional receiving receiving antennas. The earth is big
> resistor. A connection to it does not make our stations work better.
>
> Finally, I suggest that you try to figure out how to rig one or more
> antennas that are close to resonant on the bands where you want to use
> them, feed them with coax, and put serious chokes at the feedpoint(s).
> If you have room for a G5RV (which is really a 20M antenna), you have
> room for an 80/40 fan dipole, which also resonates on 15, and is easy to
> build. And it's pretty easy to find a way to work a 20/15/10 fan. Both
> antennas are better performers than that G5RV.
>
> 73, Jim K9YC
>
>
> _______________________________________________
> RFI mailing list
> RFI at contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
>


-- 

*Dave - WØLEV*