[RFI] New RFI

[Dave Cole]

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
>>>
>>>
>>>
>>> _______________________________________________
>>> RFI mailing list
>>> RFI at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/rfi
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> 
>