collection of information to assist those in locating powerline arc
amateur radio licensee W4NBO (formerly AF4O)
as information is available
FCC License Data: https://wireless2.fcc.gov/UlsApp/UlsSearch/license.jsp?licKey=4439683
Click here to jump to Secondary Source Page. Currently In Progress
Primary Source - Resolved!
Frequency Interference in the area of West End Street and Clifft
Street in Bolivar, Tennessee
Even during these long appearances and disappearances source is
intermittent. Such that the source may not be active when a RFI
location crew is able to come by. I am in a
rural area and it takes time for them to come out.
power company graciously offered to request a TVA rfi location crew to
come out but my concern was that they would come out and the source not
be active due to its highly intermittent
nature, thus the location efforts here.
- Reappeared January 2021 and was active often although intermittent until a severe winter weather event in February
- Disappeared mid February and reappeared early April 2021
- When absent, noise levels are blissfully quiet.
Identification of source type
120Hz spikes from a typical recording of the rfi as seen on Audacity
– Click on to hear/see
11, 2021 Audio
12, 2021 Audio/Video
Triangulation & Final Identification
Either there is 2 sources or I
mistakenly tracked to pole on West End Street. Was tracking for maximum
noise and not noise pattern, see below.
The source on West End is still active although diminished to where it is not seriously affecting my station at this time.
Direction finding with my 6 meter beam at 40' proved to be misleading.
Likely due to the close proximity of the source pole some 50' away.
- Initial HF triangulation with FT817 on AM and loop tuned to 14.1mhz
- 145 Mhz Triangulation Gear: 440Mhz
HandiTalkie receiving retransmitted audio from HF Transceiver tuned
near 10Mhz monitoring the Arc RFI
145Mhz HandiTalkie on AM and 3 element handheld yagi
- Listening to both HandiTalkies to compare noise pattern to make sure I was tracking the correct noise.
- This lead me to the pole at the back corner of my lot behind my house
- Noise ceased before I could use my Ultrasonic dish due to a malfunction of the dish and a subsequent winter storm.
Update; Source reappeared in early April 2021 and was able to locate on this same pole with the ultrasonic dish.
The arcs are tiny but visible. They remind me of tiny welding arcs.
One appeared to move an inch or so on the wire and would come
- After locating with the ultrasonic dish, after dark was able to
see the arc's with binoculars (Red arrows in the pictures below).
and go. The others were constant. My digital camera faintly picked up
one of the arcs but little can be seen of the pole in the dark.
A night vision camera maybe something to add to my growing rfi toolbox.
Weather Log - To correlate weather conditions so those
involved with finding the arc will have a better
chance of being
present when the arc is active. Readings taken on 80 meter SSB for
Best Practices and notes for this hunt
indicative of a power arc.
- House. Pulled the main breaker on the house while listening to HF on battery power.
- Type identification I recorded the audio of the noise and used the program Audacity to analyze and identify the 120hz spikes
on AM mode and a 2m yagi built with light weight metal tape measure elements. Retransmitted the noise from my HF receiver
- Triangulate. I use a FT817 on AM mode and several hf loops. As I got closer to the source (a utlity pole) switched to a FT-60
to a HT on 440mhz FM thus being able to compare the noise pattern with the tracking HT/Yagi. Waiting until the
noise has a distinctive pattern is helpful.
but are expensive at this time. There are many youtube videos on how to remove the IR filter lens of a standard digital camera
- Ultrasonic. Able to narrow area of the pole to 2-3 feet. I built the W1TRC dish in the QST article years ago.
- Binoculars. Was lucky that I could see these arcs at night and no streetlight on this pole or nearby.
- A good night vision hunting camera maybe a good item to add to my rfi tools. A thermal imaging camera would be nice
to allow the CCD to be sensitive to IR light. Might be a worthwhile project
Wow, just Wow. Crews did the repairs requested
some 3-4 days after requested. The local utility was nothing short of
cooperative and willing
to work to resolve the issue best they could without outages. Its now
about 3-4 days post repair as of this writing and the overwhelming
of the main source of 120hz noise is gone.
Even during times of lull's as noted in the logs above, I would occassionally hear a second or so of loud pop. Not even hearing
that anymore from the main source. One word of caution to myself
though. Much of the hardware which built up the path to arc remains so
could reoccur over time but its anyones guess as to how long it will
take if ever since the wire is further away from the hardware where the
likely built up.