RFI
[Top] [All Lists]

Re: [RFI] Not your typical invisible fence RFI

To: "Hare, Ed, W1RFI" <w1rfi@arrl.org>
Subject: Re: [RFI] Not your typical invisible fence RFI
From: David Eckhardt <davearea51a@gmail.com>
Date: Mon, 24 Jan 2022 00:52:14 +0000
List-post: <mailto:rfi@contesting.com>
Ed, please let me know why I did not find it under the listing on the OET
for the FCC ID number.  That is usually where I find such things.  Please
educate me on how you found it.

Dave - WØLEV

On Sun, Jan 23, 2022 at 10:49 PM Hare, Ed, W1RFI <w1rfi@arrl.org> wrote:

> I found the certification record easily.
>
>
>
> https://apps.fcc.gov/oetcf/tcb/reports/Tcb731GrantForm.cfm?mode=COPY&RequestTimeout=500&tcb_code=&application_id=rQqvlnXl0jI%2BsFf%2Fvos1Hw%3D%3D&fcc_id=KE3-3002587
> FCC - OET TCB Form 731 Grant of Equipment Authorization
> <https://apps.fcc.gov/oetcf/tcb/reports/Tcb731GrantForm.cfm?mode=COPY&RequestTimeout=500&tcb_code=&application_id=rQqvlnXl0jI%2BsFf%2Fvos1Hw%3D%3D&fcc_id=KE3-3002587>
> OET TCB Form 731 Grant
> apps.fcc.gov
> It is not a Class B device; it is an intentional emitter.  The rules for
> emissions from intentional emitters, when coupled with a flawed
> extrapolation method that the FCC defines is rather high by
> radiocommunications standards.  The harmonic suppression required in the
> rules is essentially 0 dB, with spurious emissions limited to the same
> levels as would be intentional emissions on the same frequency.
>
> Fortunately, the cure worked.  Interestingly, ARRL has received very few
> complaints about these, although by the look of the rules and the
> certification test report, it looks like interference is likely.
>
> Ed
>
>
> ------------------------------
> *From:* RFI <rfi-bounces+w1rfi=arrl.org@contesting.com> on behalf of
> David Eckhardt <davearea51a@gmail.com>
> *Sent:* Sunday, January 23, 2022 1:06 PM
> *To:* Don Kirk <wd8dsb@gmail.com>
> *Cc:* RFI <rfi@contesting.com>
> *Subject:* Re: [RFI] Not your typical invisible fence RFI
>
> There is no record on the FCC OET site for KE3-3002587 which is shown on
> the image of the label as the FCC ID number for the wireless transmitter -
> Part 15, Class B, Subpart B, intentional radiators.  However, if I input
> only the Grantee Code of KE3, indeed, all kings of pet care products are
> shown.  This might be a knockoff with a bogus FCC ID????  Also, as a Class
> B product - home and small office - the FCC logo is required on the
> regulatory label.  It is absent.
>
> Dave - WØLEV
>
> On Sun, Jan 23, 2022 at 3:23 PM Don Kirk <wd8dsb@gmail.com> wrote:
>
> > I just uploaded a video onto YouTube that documents wideband RFI on 20
> > meters that I tracked down to my neighbors invisible fence transmitter,
> and
> > it's not the typical approximate 7 or 10 KHz interval RFI encountered
> with
> > inground invisible fences.  The RFI which is at least 150 KHz wide at my
> > house moves around based on outdoor temperature and on warmer winter days
> > it drops down to slightly below the 20 meter band.
> >
> > I was hoping the problem was with the wall-wart power supply feeding the
> > transmitter but it was not.  The transmitter has battery backup and the
> RFI
> > is still present with the wall wart unplugged, and we also tried a linear
> > lab grade power supply in place of the 19.0 Vdc 1 amp wall wart with no
> > noticeable difference in the level of RFI at my house.
> >
> > Unfortunately the transmitter is not part of a DIY system so the
> > manufacturer (Radio Systems Corporation) requires that we deal with the
> > local "Invisible Fence" Dealer which is our next step.
> >
> > An interesting note is that when I first tracked the RFI down to my
> > neighbors home I wound up near the main circuit breaker box.  We then
> tried
> > sniffing the circuit breakers with a very small loop to see what circuit
> in
> > the house the RFI was originating (assuming the RFI was being conducted
> on
> > house wiring) and this technique typically works great.  We did not
> detect
> > the RFI on 20 meters on any of the circuit breakers which was interesting
> > because the RFI was strong near the main circuit breaker box.  It turned
> > out that the invisible fence transmitter is just a few feet away from the
> > main circuit breaker box which explained why the signal was strong near
> the
> > main circuit breaker box.
> >
> > For those interesting here is a link to the video documenting the RFI:
> > https://youtu.be/rHABjR0GZWg
> >
> > P.S. I have great neighbors that are wonderful to work with on RFI
> issues.
> >
> > 73,
> > Don (wd8dsb)
> > _______________________________________________
> > RFI mailing list
> > RFI@contesting.com
> > http://lists.contesting.com/mailman/listinfo/rfi
> >
>
>
> --
> *Dave - WØLEV*
> *Just Let Darwin Work*
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
>


-- 
*Dave - WØLEV*
*Just Let Darwin Work*
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
<Prev in Thread] Current Thread [Next in Thread>