You may have to totally enclose the electronics with aluminum foil. I used
one of these a couple of months ago and had to do a major shielding job to
get rid of the hum which overwhelmed the operation of the unit. You may
also have to common (ground) the microphone mount, itself. It's quite a
good instrument after some major surgery to basically place the electronics
from the microphone mount through the electronics in a Faraday cage.
Remember to treat all conductors in and out of that implanted Faraday cage
within the cage. MFJ should have addressed this short coming, but plastic
is the least expensive option.
Dave - WØLEV
On Sat, Apr 17, 2021 at 4:10 AM Hisashi T Fujinaka <htodd@twofifty.com>
wrote:
> Good to hear yours works with no mods. I was getting a lot of hum on
> mine so I was thinking of modifying it. I like using MFJ equipment as a
> starting point.
>
> On Sat, 17 Apr 2021, David Eckhardt wrote:
>
> > that is a good tool for coronal and arc discharges.
> >
> > Dave - W?LEV
> >
> > On Fri, Apr 16, 2021 at 9:31 PM Christopher Wawak <kc2ieb@wawak.org>
> wrote:
> >
> >> Hi all! I ended up splurging on this doohickey -
> >> https://mfjenterprises.com/products/mfj-5008 . It's an ultra-sonic
> >> receiver
> >> that purports "to pick up the noise generated by the corona discharge
> and
> >> arcing connections". For those who may not be following my saga, I
> >> determined using a portable SDR radio that the same noise that
> obliterates
> >> 40m up through 10m comes strongest from one of two electric poles near
> my
> >> house. No other poles exhibit the noise. Using the MFJ-5008, I
> immediately
> >> heard a very strong ringing from one of the two poles, which doesn't
> show
> >> up when I point it at other poles, houses, etc. There's a little sight
> hole
> >> you can use to pinpoint the noise, which I did - it seems near the top
> of
> >> the pole is where the sound is loudest. Very easy to use, and seemed to
> >> work as advertised. Totally understand why this is expensive, it's a
> very
> >> niche item. I'll need to find a lot of RFI to make up the price tag, but
> >> additional evidence helps!
> >>
> >> I called the power company, who initially said they'd have a crew out
> in 4
> >> hours. After days with no visit, and numerous calls to PSEG, they have
> no
> >> information to provide. I filed a complaint with the NJ Board of Public
> >> Utilities asking that they follow up with PSEG and compel them to
> consider
> >> my complaint. If anyone has a contact with PSEG, I'd really appreciate a
> >> connection off list.
> >>
> >> If folks are interested, I'll try to make a little video of using the
> >> device. Also, if you're in the Southern NJ area and need to borrow it, I
> >> accept beer! :)
> >>
> >> Thanks again for the help and moral support!
> >>
> >> 73 Chris KC2IEB
> >>
> >> On Sun, Apr 11, 2021 at 3:05 PM Christopher Wawak <kc2ieb@wawak.org>
> >> wrote:
> >>
> >> > Hi All!
> >> >
> >> > I wanted to share where I was currently with my noise issue.
> >> >
> >> > Surprise surprise, I don?t think it?s solar panel noise! After doing
> some
> >> > more direction finding, I seem to have nailed the source down to
> either
> >> my
> >> > electric meter, or one of two telephone poles. Initially I used an
> IC-705
> >> > with the Flag antenna that was in QST recently and a DXE
> >> > preamp/attenuators. Once I verified the signature of the same noise
> that
> >> > I?m getting in my antennas, I went back with a cheap AM antenna,
> since it
> >> > was easier to record a video.
> >> >
> >> > I do have an RFI log I can share on request.
> >> >
> >> > I?m curious what you all think of my radio direction finding based on
> a
> >> > short video I created.
> >> >
> >> > https://youtu.be/v3oJLtUBrlc
> >> >
> >> > 73
> >> > KC2IEB Chris
> >> >
> >> > On Sun, Mar 14, 2021 at 3:00 PM Christopher Wawak <chris@wawak.org>
> >> wrote:
> >> >
> >> >> Hi RFI List,
> >> >>
> >> >>
> >> >> I'm faced with S7-S9 noise across 40m-15m at 200khz intervals. I'm
> >> >> looking for assistance resolving this RFI I suspect is coming from a
> >> >> neighbor's solar installation. The owners are elderly, and I'm not
> sure
> >> >> they'll understand and be able to remedy the situation. HF is next to
> >> >> unusable.
> >> >>
> >> >>
> >> >> Some questions:
> >> >>
> >> >> 0. So far, do I seem on the right path?
> >> >>
> >> >> 1. What tactics have worked in the past with getting owners to
> respond?
> >> >>
> >> >> 2. Right now I have an AH-4 with a wire antenna. If I switched to,
> say,
> >> a
> >> >> fan dipole or a beam antenna would i be able to reject the solar
> panel
> >> >> noise? If my antenna were higher up, would that help?
> >> >>
> >> >> 3. Am I doomed to not have workable HF at home?
> >> >>
> >> >>
> >> >> 73 Chris KC2IEB
> >> >>
> >> >>
> >> >> (if the pictures are filtered, click here
> >> >> <
> >>
> https://docs.google.com/document/d/e/2PACX-1vSKoiPx-5huAG5M1gLmYFyMPRZ_WY0PxxoC-CH7c-dpXMQZzHuvLzNX2AB8_nb8RIsN7Ri0rmXJp6Ju/pub
> >> >
> >> >> )
> >> >>
> >> >> RFI Location
> >> >>
> >> >> Appears to be coming from solar panels on a house behind my own,
> about
> >> >> 275? away. I traced this with a loop antenna and a cheap AM radio
> >> >> following to where the noise seemed loudest.
> >> >>
> >> >> Characteristics
> >> >>
> >> >> Heavy S7+ ?hash? noise every ~200 khz, starting around 40m and going
> all
> >> >> the way up through 15m.
> >> >>
> >> >>
> >> >> Generally starts an hour or two after sunrise, and shuts down before
> >> >> sunset.
> >> >>
> >> >> Noise Log
> >> >>
> >> >> 3/13/2021
> >> >>
> >> >> 4:00 PM Local - https://www.youtube.com/watch?v=QQZr1xXIf0Y whole
> house
> >> >> power off test @ 3:14 in the video - no improvement
> >> >>
> >> >>
> >> >> Gone by 7:53 PM
> >> >>
> >> >> 3/14/2021
> >> >>
> >> >> 8:38 am
> >> >>
> >> >> Some squiggles
> >> >>
> >> >> Showed up almost on the dot at 9am
> >> >>
> >> >> It?s moving down the band some
> >> >>
> >> >> Most noticeable from 20m on up
> >> >>
> >> >> .
> >> >>
> >> >>
> >> >>
> >> >> --
> >> >> -- Chris
> >> >>
> >> >
> >> _______________________________________________
> >> RFI mailing list
> >> RFI@contesting.com
> >> http://lists.contesting.com/mailman/listinfo/rfi
> >>
> >
> >
> > --
> > *Dave - W?LEV*
> > *Just Let Darwin Work*
> > _______________________________________________
> > RFI mailing list
> > RFI@contesting.com
> > http://lists.contesting.com/mailman/listinfo/rfi
>
> --
> Hisashi T Fujinaka - htodd@twofifty.com
> BSEE + BSChem + BAEnglish + MSCS + $2.50 = coffee
>
--
*Dave - WØLEV*
*Just Let Darwin Work*
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