i had some trouble w/a older unit, specifically it was the battery charger
ckt. wouldn’t be surprised if something in there was ‘off’
> On Feb 16, 2026, at 3:49 PM, David Eckhardt <davearea51a@gmail.com> wrote:
>
> I'm sure there is lots of digital circuitry within the box. Digital
> circuitry = RFI ! ! ! I'd suggest temporily disconnecting the battery.
> Let ADT know before you do so or they may interpret that as in ingress.
> Also disconnect their dable, if any. I'll be with those two actions, the
> RFI will cease.
>
> Have you "sniffed" the ADT box and installation with a spectrum analyzer
> and a small (maybe 5-cm in diameter or so) loop?
>
> Dave - WØLEV
>
> On Mon, Feb 16, 2026 at 8:26 PM Joseph Bouchard <joek1vw@gmail.com> wrote:
>
>> Hi,
>>
>> We have a club station at a museum and are chasing down RFI (KB1BSM). I
>> threw every breaker in the building with someone watching the panadapter.
>> It didn’t kill the particular noise we are chasing, which shows an S9
>> harmonic about every 34khz on 20m.
>>
>> Then someone said “we have an ADT security system with its own battery
>> backup.” They think they can call ADT and get them to remotely shut it down
>> temporarily for a test, but I’m a little skeptical… if they are talking to
>> it remotely, it’s not really dead is it? I tried to get a model number but
>> all I see is a red metal lock box with a little ground plane antenna, about
>> 6” tall. I suspect it’s a cellphone antenna. I don’t expect that UHF
>> radio is causing us problems on HF, but the system of sensor could be noisy.
>>
>> Anyway, my question for the group, are ADT security systems a known
>> culprit for RFI?
>>
>> Thank you,
>> Joe K1VW
>> _______________________________________________
>> RFI mailing list
>> RFI@contesting.com
>> http://lists.contesting.com/mailman/listinfo/rfi
>>
>
>
> --
>
> *Dave - WØLEV*
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|