[RFI] From: [irca] Strange RFI

[Dave (NK7Z)]

I have seen something like that here as well...  You will need to gather 
a lot more info, and do some hunting...

See:

https://www.nk7z.net/sdr-rfi-survey-p1/

This will help you define the schedule the RFI keeps...

I suspect what I am seeing, is a variable duty cycle fan...  No reason 
to suspect this other than a guess at it...

The RFI I see, seems to be related to outside temperature...  During 70 
to 75 degree weather, I almost never see it.  The colder, or hotter it 
gets the more I see it.  It also changes activity at night...

All of this is fun, but does not locate the RFI...  It's loop and radio 
time...

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

On 11/14/23 08:55, Facility 406 wrote:
> Received the following message through another forum this morning. 
> Peculiar RFI I've not seen, or heard before.
> 
> Ideas?
> 
> Original poster email address is:
> 
> mark at spacetubes.com
> 
> Original message below:
> 
> 
> 
> Wondering if anyone has seen any RFI that looks like this.
> 
> https://spacetubes.com/DX/Digital.RFI.Lower.AM.Band.Start--2023.Nov.14--sdkaz--perseus.mp4
> 
> https://spacetubes.com/DX/Digital.RFI.Lower.AM.Band.End--2023.Nov.14--sdkaz--perseus.mp4
> 
> The first link shows it starting up, then it goes like that for a while 
> (sometimes a long time - half an hour or more), then it ends like what's 
> shown in the second link,
> 
> Then it can be quiet for a random amount of time, before it starts up 
> again.
> 
> Mark Pettifor
> Goshen, IN -- en71ao
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