[RFI] Mystery noise

[David Eckhardt]

Your "secret" is safe, here!

But, I have a rather monstrous common mode choke on the new
refrigerator/freezer power cord.  At least that was accessible unlike the
clothes washer/dryer and dish washer, and a few additional SMPS's in other
appliances.

And.....if I get serious about a specific radio astronomy associated
project, only the computer serving that project is on.  All others are off
and the internet is OFF, including the wireless router. Not just OFF, but
denied AC power!

Dave - WØLEV

On Fri, Aug 13, 2021 at 5:31 PM Hare, Ed, W1RFI <w1rfi at arrl.org> wrote:

> Every switcher that has caused me interference has been in my own home,
> but don't let on. If it ever got out that W1RFI had RFI, my reputation
> would be ruined. 🙂
>
> ________________________________
> From: RFI <rfi-bounces+w1rfi=arrl.org at contesting.com> on behalf of Jim
> Brown <jim at audiosystemsgroup.com>
> Sent: Wednesday, August 11, 2021 4:42 PM
> To: rfi at contesting.com <rfi at contesting.com>
> Subject: Re: [RFI] Mystery noise
>
> Great description. And when dozens of these free running sources are
> present (those in our own home and those in our neighbors' homes), the
> result can combine to look like broadband noise. This piece, which ran
> in NCJ several years ago, provides methods for finding and killing these
> sources. The process does NOT start with direction-finding -- that comes
> later after we've cleaned up our own homes.
>
> 73, Jim K9YC
>
> On 8/11/2021 12:21 PM, Hare, Ed, W1RFI wrote:
> > Switching regulators make noise ever N kHz, with N being the free
> running frequency of the internal circuitry.  The noise can be almost a
> carrier to just broadband buzz every N kHz, with a 120- or maybe 60-Hz
> component.
> > They are also drifty with temperature, change frequency with load
> changes and when there is a voltage dip or surge, they do a little burble
> or change in frequency to match.
>
> _______________________________________________
> RFI mailing list
> RFI at contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
> _______________________________________________
> RFI mailing list
> RFI at contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
>


-- 
*Dave - WØLEV*
*Just Let Darwin Work*