Topband: RFI powerline ?

[Don Kirk]

Hi Andy,

I agree with David (K1WHS) that your RF Spectrum waterfall display does not
look like powerline noise as it shows very repeatable bright and dark bands
and the bright bands are equally spaced approximately if not exactly 500 Hz
apart from each other and this is not what you would typically see for
power line noise.   I believe the IC-7851 has an audio spectrum display and
audio waterfall display which also would be interesting to view (view them
with your radio in AM mode using a wide filter setting).  The IC-7851 even
has an audio oscilloscope display which is interesting if it is power line
noise but I won't get into those details right now to keep things simple.

Keep us posted.

73,
Don (wd8dsb)

On Tue, Jan 11, 2022 at 9:25 AM David Olean <k1whs at metrocast.net> wrote:

>
> Hello Andy,
>
> It looks like some form of man made QRM, and not power line noise. I am
> very familiar with powerline noise, but our noise is at 120 Hz and yours
> will be at 100 Hz, 60 vs 50 Hz) so it should sound a lower pitch than
> what I am used to, but the waterfall display shows those evenly spaced
> groups of noise and that does not look like power line noise.
>
> Dave K1WHS
>
> On 1/11/2022 4:37 AM, Karel Matousek wrote:
> > Hi Andy.
> >
> > I do have the same noises problem over here as you have.
> >
> > I found that it isn’t a 110 KV powerline noise, but probably a
> > broadband noise is coming from the direction 10 ° here in JO60OK. It's
> > very annoying. On the 800 meters US beverage (300°) the noise is S4,
> > but on my second stateside 4 EL bidirectional (330°/150°) broadside
> > K9AY array 84 meters apart uses the 0° hybrid combiners it is very
> > strong. It interrupts all night. At first, I thought it was a local
> > noise made by switching power supply. I’m so sorry, but I do not have
> > the beverage pointing directly to the north. During the day, the band
> > is clean, without noise, but when getting dark, the noise begins to be
> > heard and after midnight it is then very strong.
> >
> > https://drive.google.com/drive/folders/1DhkrxjaX0Mv171psVF4F_cfOHFB7hEX9
> >
> > Karel OK1CF
> > ______________________________________________________________
> >> Od: "Andree DL8LAS via Topband" <topband at contesting.com>
> >> Komu: "topband at contesting.com" <topband at contesting.com>
> >> Datum: 11.01.2022 09:21
> >> Předmět: Topband: RFI powerline ?
> >>
> > Hey gentlemen,
> > I have a powerline 110KV nearby my beverages....this is the sound in
> > AM, not strong but  also not good.Is this RFI normal from the line  or
> > is this  an insulator or another problem?Here you can see a short
> > video and hear the signal  from today.
> > https://www.youtube.com/watch?v=Oue6JGBKzgg
> > <https://www.youtube.com/watch?v=Oue6JGBKzgg>
> > 73 Andy DL8LAS
> >
> >
> > www.dl8las.com
> > www.swing-company-bigband.de/
> > www.uni-big-band-kiel.de/
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