[RFI] New RFI

[K9MA]

It just depends on the neighbor. I guess I'm very fortunate that aside 
from the lady 25 years ago who was going to "Shoot my tower down", my 
neighbors have been very cooperative. Had I not gone in their homes, the 
problems would not have been solved. There was the family with the noisy 
LED light supply, and the woman next door with the plasma TV. In the 
former case, I paid part of the cost of the new power supply; in the 
latter, I bought her a new TV.  Both worthwhile investments in lower 
noise and good neighbor relations. In another case last spring, when I 
was trying to track down some line noise, it somehow tricked me into 
believing it came from a particular house. I knocked on the door, and 
the woman who lived there gave me her phone number. (This was pandemic 
time, so I had no intention of going in the house.) I later called her 
and she tried to track it down, even turning off the main breaker and 
having to reset all the clocks. Turned out to be a false alarm: the real 
noise source was a power pole across the street. I still don't know why 
that one day everything pointed to that house.

On the plus side, I haven't had an outgoing RFI complaint in many years. 
I used to have to put filters on all the neighbors' telephones. Many new 
neighbors have moved in, and I always tell them to let me know if they 
hear funny beeps coming out of electronic devices. Unfortunately, most 
of the RFI is going the other direction lately.

73,
Scott K9MA

On 1/12/2021 5:07 PM, Dave Cole wrote:
> Hi Pete,
>
> As the previous poster mentioned, this is more geared towards new, or 
> unknown conditions...  Most of the issues across the past five years, 
> here in Eugene Oregon, are Pot Grows.
>
> Ninety percent of the growers are fine, normal folks, who quickly fix 
> things, say thanks for telling them, then offer to share, (which I 
> thank them for, but tell them no thanks), and we part with no hard 
> feelings on either side.  I may have to call on them again, so I never 
> leave them ticked off if possible.
>
> However every now and then I get a "interesting" one...  Here is a 
> short, and now humorous, (although it was not at the time), story from 
> the RFI hunting annals:
>
> RFI  starts, I trace it to a home.  I knock on the door.  The person 
> comes out and we talk a bit, all very friendly, and he indicates he 
> will fix the issue.  All while his girl friend is wandering around 
> half naked on the porch twenty feet behind him. He fixes the RFI in 
> short order, and I figure things are finished...  Oh no they are not!
>
> A few weeks later I get a call from him asking about building a 
> Faraday cage around his bed.  He now believes that the "rays" from the 
> RFI are harming him, and he wants to, (and I quote), "protect himself 
> from the RFI rays".  He has evidently been caught up in all the "5G 
> will kill you", propaganda going around, and convinced himself the 
> "RFI rays" from the grow lights will kill him in the long run.
>
> At this point, I decide I want no more to do with him at any distance, 
> and I tell him I don't know anything about how to build Faraday cages. 
> This was a few years ago ago.
>
> I was just told, a few months ago, by a neighbor, that sometime 
> shortly after my encounter with him, Law Enforcement was out for a 
> "friendly" visit-- why?
>
> Because he was in front of his house, with an AR-15, shooting at 
> Tannerite cans he had placed all around his front yard!
>
> According to the neighbor, you would hear pop, boom, pop, boom, pop, 
> boom-- which I assume is what got the police called on him.
>
> I live in a pretty decent neighborhood, not a farming community; it is 
> urban in town living, in one of the better areas in town... This was 
> two blocks from my home.  That is when I decided to NEVER enter an 
> unknown home, under any circumstances, for any reason. He seemed so 
> normal when we first chatted...
>
> That is why I take such a strong position...  Liability is only part 
> of the issue...
>
> 73, and thanks,
> Dave (NK7Z)
> https://www.nk7z.net
> ARRL Volunteer Examiner
> ARRL Technical Specialist, RFI
> ARRL Asst. Director, NW Division, Technical Resources
>
> On 1/12/21 1:22 PM, N4ZR wrote:
>> I was a little surprised by Dave's strong advice against entering a 
>> home where RFI is located.  On two occasions at my former townhouse 
>> QTH, I discovered that the source of RFI was "clickless" light 
>> switches in neighbors' houses.  This could only be identified by 
>> zeroing in on the faulty switch and toggling it off and on to confirm 
>> the find. On another, the source was the thermostat on an 
>> electrically-heated dog dish.  Without entering the yard (with the 
>> owner's permission, of course), I would never have found it.
>>
>> Granting that these two episode occurred 20 and 10 years ago, I think 
>> points 4-7 are unduly absolute - it depends a lot on the neighborhood 
>> and the neighbor.
>>
>> 73, Pete N4ZR
>> Check out the new Reverse Beacon Network
>> web server at <http://beta.reversebeacon.net>.
>> For spots, please use your favorite
>> "retail" DX cluster.
>>
>> On 1/12/2021 12:02 PM, Dave Cole wrote:
>>> Some of the techniques for fixing these issues are:
>>>
>>> 1.  I added a attenuator to the MFJ device.  I moved the actual 
>>> receiver down the mast, and ran coax, then added a step attenuator.
>>>
>>> 2.  Once I "think" I have the signal located, and, I have contacted 
>>> the person responsible, I set up a test whole home shutdown with 
>>> them, (if possible), while listening to the RFI both at the remote 
>>> site using a handheld radio, and at my home, via a cell call to my 
>>> landline, with the handset set in front of the speakers of my main rig.
>>>
>>> 3.  When I first approach, I have a portable radio on, and the RFI 
>>> slightly too loud.  That helps in convincing folks that the RFI is a 
>>> problem...  I think.
>>>
>>> 4.  I never enter a home, period for obvious reasons.
>>>
>>> 5.  I never approach alone, period, again for obvious reasons.
>>>
>>> 6.  I never suggest a fix, period.  I tell them what has worked in 
>>> the past for me...  If I suggest a fix, and they blow up the 
>>> install, and their home burns down, my liability is increased.
>>>
>>> 7.  I never tell the person responsible it is fixed, I tell them 
>>> that it no longer is an issue for me.  Why?  If I tell them it is 
>>> fixed, and later on, the local PD or whoever approaches them, they 
>>> can say, so and so said it was fixed, and your liability increases...
>>>
>>> 73, and thanks,
>>> Dave (NK7Z)
>>> https://www.nk7z.net
>>> ARRL Volunteer Examiner
>>> ARRL Technical Specialist, RFI
>>> ARRL Asst. Director, NW Division, Technical Resources
>>>
>>> On 1/12/21 8:31 AM, K9MA wrote:
>>>> I've also had success with the MFJ-856. However, when you get close 
>>>> to a strong source, it can overload and lock up. My solution was to 
>>>> make two wide straps of thin aluminum with which to short out the 
>>>> antenna, receiver, or both. When I'm right next to a very strong 
>>>> source, I can hear it with both straps on.
>>>>
>>>> The other caveat, which I've mentioned before here, is to make sure 
>>>> you're hearing the same source that's causing the problem. The 
>>>> MFJ-856 is very sensitive, and will detect a lot of weak sources 
>>>> which, at least in an urban area, are usually not the main problem.
>>>>
>>>> 73,
>>>> Scott K9MA
>>>>
>>>>
>>>>
>>>> On 1/12/2021 7:25 AM, Dave Cole wrote:
>>>>> Hello,
>>>>>
>>>>> I have some RFI location information at:
>>>>>
>>>>> https://www.nk7z.net/i-have-rfi-now-what-locating-it/
>>>>>
>>>>> I use the MFJ-856, (https://mfjenterprises.com/products/mfj-856), 
>>>>> when looking for VHF RFI.  It will pinpoint an RFI source and in 
>>>>> most cases you can tell which part of the house the RFI is coming 
>>>>> from, if you are on the sidewalk in front of the home.
>>>>>
>>>>> Your RFI could be anything, is it on a schedule, does it change 
>>>>> strength, lots of questions to answer first.
>>>>>
>>>>> IDing via signature can sometimes work, (not too often), but 
>>>>> nothing has worked for me better than getting out on foot and 
>>>>> looking for the RFI source.
>>>>>
>>>>> Once you have it located that is another entirely different matter.
>>>>>
>>>>> 73, and thanks,
>>>>> Dave (NK7Z)
>>>>> https://www.nk7z.net
>>>>> ARRL Volunteer Examiner
>>>>> ARRL Technical Specialist, RFI
>>>>> ARRL Asst. Director, NW Division, Technical Resources
>>>>>
>>>>> On 1/11/21 8:45 PM, RALPH GRANCHELLI wrote:
>>>>>> Hello inteference investigators,
>>>>>>
>>>>>> I have new RFI issue that started about a week ago.
>>>>>>
>>>>>> I have eliminated the house /  items as a source.
>>>>>>
>>>>>> Killed all breakers, ran the XCRV from batt. No change. 
>>>>>> Disconnected ext antenna, used in house antenna and no noise. So 
>>>>>> noise coming in from ext antenna.
>>>>>>
>>>>>> The RFI is strongest on 80 meters however it is present up to vhf 
>>>>>> with diminished magnitude.
>>>>>>
>>>>>> I took a screen shot of it on the spectrum scope.
>>>>>>
>>>>>> Does anyone recognize the signature?
>>>>>>
>>>>>> https://www.youtube.com/watch?v=uOdzw2ev5eE 
>>>>>> <https://www.youtube.com/watch?v=uOdzw2ev5eE>
>>>>>> <https://www.youtube.com/watch?v=uOdzw2ev5eE 
>>>>>> <https://www.youtube.com/watch?v=uOdzw2ev5eE>>
>>>>>> TNX & Rgds,
>>>>>>
>>>>>> N6XLQ
>>>>>>

-- 
Scott  K9MA

k9ma at sdellington.us