You are correct Charlie,
However, in my classes I used an ultra sound transmitter to demo the use of the
RE Hotstick Line sniffer, the UE 2000 and the RE 250. I would show a slide of a
7.2 kV pin type insulator and reflect the corona onto the screen where the
insulator was and do discharge corona. So while showing the Hotstick demo I
would detect the corona on the screen using the sniffer and someone would
always ask why the corona on the screen? My answer was and is, because it was
noisy when I took the picture. So ultrasound does reflect and can go around
hardware, but not more than a couple feet!
RFI Services
Michael C Martin
51 W Bay Front Rd
Lothian, MD 20711
240-508-3760
mike@rfiservices.com
www.rfiservices.com
FCC P2-4-10920
-----Original Message-----
From: RFI <rfi-bounces+mike=rfiservices.com@contesting.com> On Behalf Of
n0tt1@juno.com
Sent: Friday, February 02, 2024 6:55 PM
To: RFI@contesting.com
Subject: Re: [RFI] UPDATE re: Source power pole located - but wonder which
components most likely temperature sensitive
>"ONE WONDERS then how effective an ultrasonic micro 'dish' works if
>the same principle applies, with hidden arcs and the like?"
Ultrasonic sound is high frequency audio and as such it generally won't travel
around objects.
Consider the US detector as strictly line of sight instrument. It won't detect
sound coming from say, arcs inside of transformers or lightning arresters.
Even a lineman's hand is enough to block a US sound when he's near the source.
Charlie, N0TT
On Fri, 2 Feb 2024 21:29:49 +0000 (UTC) AA5CT via RFI <rfi@contesting.com>
writes:
> As was written: "Of course, something with an internal arc or hidden
> arc will be hard to see using UV camera..".
> ONE WONDERS then how effective an ultrasonic micro 'dish' works if the
> same principle applies, with hidden arcs and the like?
> .
> Since I have only used MW/HF DF gear, VHF with an omni antenna and UHF
> with a small Yagi to troubleshoot/locate these things I have no
> hands-on experience with other gear and must rely on vendors and
> written evaluation reports and articles such as I cited..
> I include one more article link that may be of
>
interest..https://www.inmr.com/uv-ir-imaging-of-defects-in-hv-components/
> .I note in the literature that corona arcs/arcing (if visible, would
> be seen w/UV camera) are what produce the acoustical noise that may be
> received with ultrasonic gear, but I have not researched that area
> like for UV cameras. It would seem then that acoustical / ultrasonic
> detection has the same limitation then that UV cameras have.
> Discussion?
> .de AA5CT Jim
>
> On Friday, February 2, 2024, 3:02:59 PM GMT-6, Michael Martin
> <mike@rfiservices.com> wrote:
>
> Close to 99% of overhead Powerline interference noise sources will
> not be visible with UV cameras or Corona cameras. Most of what those
> two cameras see are not the interference sources affecting your radio
> system.
> Michael Martin
> RFI Services
> 51 W Bay Front Rd
> Lothian, MD 20711
>
> 240-508-3760
> mike@rfiservices.com
> www.rfiservices.com
> On Fri, Feb 2, 2024, 2:57?PM AA5CT via RFI <rfi@contesting.com>
> wrote:
>
> We've been here before. Actual arcs exhibit in UV spectrum, and UV
> sensitive camera are used by experts in this field to find the arcing
> hardware. Of course, something with an internal arc or hidden arc will
> be hard to see using UV camera..
> Some camera models place the UV corona image upon a visual-light image
> of the scene since otherwise no image will be seen on a UV only
> camera, unlike what is often seen on an IR camera.
> .
> From:
> .
> https://www.inmr.com/infrared-uv-inspection-of-overhead-lines/.
> Detecting Corona on Power Lines
> .
> Infrared (IR) detection technology, while ideal in identifying hot
> spots in electrical power systems, has limited value when it comes to
> detecting corona activity. Experience shows that only advanced stages
> of corona can sometimes become visible using an infrared camera..
> The ideal tool to detect corona activity is a solar blind UV camera.
> .
> An example of what is seen with a UV overlay + visible camera combo.
>
>
> https://youtu.be/OtvfQ1II_ME?t=32
>
> Also:
> .
> https://ofilsystems.com/uv-inspection/
>
> de AA5CTJm
>
> On Friday, February 2, 2024, 12:34:43 PM GMT-6, Lee STRAHAN
> <k7tjr@msn.com> wrote:
>
> Hi Charlie and all,
> John Fluke company has some new equipment that senses IR and I
> believe they add ultrasonic for their new remarkable sensor capable
> of use with power lines.
> " https://www.fluke.com/en-us/products/thermal-cameras";
> A bit on the spendy side. I remember their new product
> announcement showing power line use but do not recall their specific
> product numbers.
> Searching their site.
> I Found this. "
> https://www.fluke.com/en-us/learn/blog/leak-detection/corona-discharge";
> It's an ii900 from Fluke
> Lee K7TJR OR.
>
>
> -----Original Message-----
> From: RFI <rfi-bounces+k7tjr=msn.com@contesting.com> On Behalf Of
> Charles Gallo
> Sent: Friday, February 2, 2024 7:42 AM
> To: Rfi List <rfi@contesting.com>
> Subject: Re: [RFI] UPDATE re: Source power pole located - but wonder
> which components most likely temperature sensitive
>
> I know HV lines are surveyed with drones in at least some locations.
> Usually the company applies for a beyond visual line of sight
> (BVLOS) waver, and they use drones with thermal imaging and CM
> accuracy for location
> --
> 73 de KG2V
> Charlie
>
> > On Feb 2, 2024, at 10:28?AM, Alan Higbie <alan.higbie@gmail.com>
> wrote:
> >
> > ?
> > *I'M CURIOUS*:
> >
> > - Is there some new technology being used for surveying lines?
> I sort
> > of recall reading something like this. Drones? SDR recording?
> > - Or, maybe this is just some guy driving around with his AM
> radio on?
> > - Is there a new version of the ultrasonic dish that is better
> than the
> > previous Radar Engineers model?
> > - What is the difference between RE models and the MFJ-5008?
> >
> > https://mfjen/
> >
> terprises.com%2Fproducts%2Fmfj-5008&data=05%7C02%7C%7C416b4c251bef4ede
> >
> d11108dc24059682%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C63842485
> >
> 3636490497%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzI
> >
> iLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=1y2NbTZ5VnjgayxM9A%
> > 2FBNgfhX%2FYWfplde66glt%2BDRhg%3D&reserved=0
> >
> > I will further update when these tickets are closed out - and the
> > defective component is positively identified.
> >
> > 73, ~ Alan K0AV
> > Colorado Springs
> > _______________________________________________
> > RFI mailing list
> > RFI@contesting.com
> > http://lists/.
> >
> contesting.com%2Fmailman%2Flistinfo%2Frfi&data=05%7C02%7C%7C416b4c251b
> >
> ef4eded11108dc24059682%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C63
> >
> 8424853636498434%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV
> >
> 2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=q%2BXkzCHj1pp
> > z2JM5n%2FeK0oJOBbWt%2BI8TH9RmeYirw64%3D&reserved=0
>
>
>
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