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Re: [RFI] KC2IEB’s RFI Journey

To: rfi@contesting.com
Subject: Re: [RFI] KC2IEB’s RFI Journey
From: Charles Plunk <af4o@twc.com>
Date: Sun, 11 Apr 2021 15:06:05 -0500
List-post: <mailto:rfi@contesting.com>
Good video.

One tip; make sure you are tracking the right noise. I found out the hard way that many power line utility devices/poles emanate "noise" when you are nearby but may not be "the" noise that you are hearing in your station receiver. A break thru on my latest hunt was I re transmitted the noise over 440mhz FM from my hf station while it had a distinctive but varying pattern. Then compared to my 2m HT on AM with portable yagi by listening to them both while triangulating. Made a world of difference to tracking the right noise.

Chuck
AF4O

On 4/11/21 2:05 PM, Christopher Wawak wrote:
Hi All!

I wanted to share where I was currently with my noise issue.

Surprise surprise, I don’t think it’s solar panel noise! After doing some
more direction finding, I seem to have nailed the source down to either my
electric meter, or one of two telephone poles. Initially I used an IC-705
with the Flag antenna that was in QST recently and a DXE
preamp/attenuators. Once I verified the signature of the same noise that
I’m getting in my antennas, I went back with a cheap AM antenna, since it
was easier to record a video.

I do have an RFI log I can share on request.

I’m curious what you all think of my radio direction finding based on a
short video I created.

https://youtu.be/v3oJLtUBrlc

73
KC2IEB Chris

On Sun, Mar 14, 2021 at 3:00 PM Christopher Wawak <chris@wawak.org> wrote:

Hi RFI List,


I'm faced with S7-S9 noise across 40m-15m at 200khz intervals. I'm looking
for assistance resolving this RFI I suspect is coming from a neighbor's
solar installation. The owners are elderly, and I'm not sure they'll
understand and be able to remedy the situation. HF is next to unusable.


Some questions:

0. So far, do I seem on the right path?

1. What tactics have worked in the past with getting owners to respond?

2. Right now I have an AH-4 with a wire antenna. If I switched to, say, a
fan dipole or a beam antenna would i be able to reject the solar panel
noise? If my antenna were higher up, would that help?

3. Am I doomed to not have workable HF at home?


73 Chris KC2IEB


(if the pictures are filtered, click here
<https://docs.google.com/document/d/e/2PACX-1vSKoiPx-5huAG5M1gLmYFyMPRZ_WY0PxxoC-CH7c-dpXMQZzHuvLzNX2AB8_nb8RIsN7Ri0rmXJp6Ju/pub>
)

RFI Location

Appears to be coming from solar panels on a house behind my own, about
275’ away. I traced this with a loop antenna and a cheap AM radio
following to where the noise seemed loudest.

Characteristics

Heavy S7+ “hash” noise every ~200 khz, starting around 40m and going all
the way up through 15m.


Generally starts an hour or two after sunrise, and shuts down before
sunset.

Noise Log

3/13/2021

4:00 PM Local - https://www.youtube.com/watch?v=QQZr1xXIf0Y whole house
power off test @ 3:14 in the video - no improvement


Gone by 7:53 PM

3/14/2021

8:38 am

Some squiggles

Showed up almost on the dot at 9am

It’s moving down the band some

Most noticeable from 20m on up

.



--
-- Chris

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