[RFI] KC2IEB’s RFI Journey

[Dave Cole]

Hi,

You might get lucky wandering around with an omni antenna on that HF 
rig, but I am thinking you need a lot more equipment to track RFI 
effectively.

As an aside, and from what I see on your poll shots, the cable 
installers in your area should learn how to install cable correctly...

I worked for a cable/TV company for 40 years, and if an installer walked 
away from that mess I see on the pole, he/she would have been fired on 
the spot.  I see at least one TV cable hanging, unterminated...

Have you done a home power off test yet?  If not, kill the main breaker 
on your house, (shutdown all sensitive equipment first), and see if the 
RFI goes away. If it does, you are in luck, just bring everything up one 
circuit at a time until you locate it.  Don't short cut this process, 
actually kill the main breaker, and any UPS for computers you have on as 
well.

If it is not in your home you might consider the following:

1.  Hand held radio.
2.  Loop antenna for HF.
3.  3 or 4 element yagi for 2 Meters, and a RX that has AM.

Those three things will get you very close to most RFI sources.

It is probably NOT your meter, all electrical cables are noisy, try 
getting close to your wired doorbell with teh handheld rig.

IMPORTANT:
Don't mess with poles, or cables, or grounds connected to poles, period. 
  Let the power company do that.  Poles are a no touch item.  Touching a 
ground on a pole can kill you if things are set up incorrectly.

POLE TOUCH = BAD

Start using the loop to locate the RFI by plotting headings on a map. 
Use the null, not the peak...

Plot a lot of headings from different areas, you should see a pattern 
start to emerge.  If you don't then you might be doing somethng wrong, 
or the source may be diffucult to locate.

Here is a link that might help you:

https://www.nk7z.net/i-have-rfi-now-what-locating-it/

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist, RFI
ARRL Asst. Director, NW Division, Technical Resources

On 4/11/21 12:05 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 at 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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