[RFI] Yagis and DFing

[Dave (NK7Z)]

Alan,

Nice setup!  Thanks for sharing, now lets apply that to Amateur Radio!

Imagine a network of hams, all with low band rigs all slaved to the same 
frequency, and all phase coherent, all reporting RFI signal arrival 
times to a cloud...  Now take that data, and treat it just like 
SHOTWATCH does for location of source...  Arrival time trilateration 
could pin a source in real time to a location...

Oh well...  Not in my lifetime...

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

On 12/31/22 07:38, Alan Higbie wrote:
> While we are daydreaming about locating RFI sources with drones - here 
> is more food for thought:
> https://www.modernpowersystems.com/features/featurepotential-game-changer-finding-imminent-power-line-faults-before-they-happen-8025876/ <https://www.modernpowersystems.com/features/featurepotential-game-changer-finding-imminent-power-line-faults-before-they-happen-8025876/>
> 
> I am thinking this might be something like the sensors & algorithm 
> system which allows for lightning detection.
> Blitzortung.org
> 
> ~ Alan K0AV
> 
> On Sat, Dec 31, 2022 at 8:03 AM Dave (NK7Z) <dave at nk7z.net 
> <mailto:dave at nk7z.net>> wrote:
> 
>     Ed,
>     I was board one day a few years ago, and took out with my mobile rig,
>     and its rear mounted vertical...  I plotted signal strength points all
>     around a known RFI source to see if an isoline map might help locate a
>     hard to find source...  It actually did indicate the area for the
>     source
>     quite accurately...  One of these days, I will actually use that
>     process
>     in a locate...
> 
>     I have this dream of a drone, a computer, more programming experience,
>     and money than I currently have...  Wouldn't it be cool to just let a
>     drone off, have it grid up an area, take signal strength readings at a
>     set altitude, then have a computer take the results and create either a
>     heat map, or an isoline map...
> 
>     Anyway, someday I may tackle that project but not soon...
> 
>     73, and thanks,
>     Dave (NK7Z)
>     https://www.nk7z.net <https://www.nk7z.net>
>     ARRL Volunteer Examiner
>     ARRL Technical Specialist, RFI
>     ARRL Asst. Director, NW Division, Technical Resources
> 
>     On 12/31/22 06:40, Hare, Ed, W1RFI wrote:
>      > If you are trying to locate a noise source, if a directional
>     antenna is available at the ham's QTH, that is the place to start.
>     It will give a general direction for that walk-around.
>      > ________________________________
>      > From: RFI <rfi-bounces+w1rfi=arrl.org at contesting.com
>     <mailto:arrl.org at contesting.com>> on behalf of Pete Smith N4ZR
>     <pete.n4zr at gmail.com <mailto:pete.n4zr at gmail.com>>
>      > Sent: Saturday, December 31, 2022 8:03 AM
>      > To: rfi at contesting.com <mailto:rfi at contesting.com>
>     <rfi at contesting.com <mailto:rfi at contesting.com>>
>      > Subject: Re: [RFI] Yagis and DFing
>      >
>      > Or use a Moxon which has a deep null off the center of the back
>      >
>      > 73, Pete N4ZR
>      >
>      > On 12/30/2022 7:19 PM, David Eckhardt wrote:
>      >> Use the sharp *nulls off the sides* of the Yagi.  They are far
>     sharper than
>      >> the "gainy" front lobe.
>      >>
>      >> Dave - WØLEV
>      >>
>      >> On Sat, Dec 31, 2022 at 12:01 AM Jim
>     Brown<jim at audiosystemsgroup.com <mailto:jim at audiosystemsgroup.com>>
>      >> wrote:
>      >>
>      >>> Remember that Yagis only have their intended directivity in the
>      >>> frequency range for which they are built.
>      >>>
>      >>> 73, Jim K9YC
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>      >>>
>      >>
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